Treatments for breast engorgement during lactation

  • Review
  • Intervention

Authors


Abstract

Background

Breast engorgement is a painful condition affecting large numbers of women in the early postpartum period. It may lead to premature weaning, cracked nipples, mastitis and breast abscess. Various forms of treatment for engorgement have been studied but so far little evidence has been found on an effective intervention.

Objectives

This is an update of a systematic review first published by Snowden et al. in 2001 and subsequently published in 2010. The objective of this update is to seek new information on the best forms of treatment for breast engorgement in lactating women.

Search methods

We identified studies for inclusion through the Cochrane Pregnancy and Childbirth Group's Trials Register (30 June 2015) and searched reference lists of retrieved studies.

Selection criteria

Randomised and quasi-randomised controlled trials.

Data collection and analysis

Two review authors independently assessed trials for eligibility, extracted data and conducted 'Risk of bias' assessments. Where insufficient data were presented in trial reports, we attempted to contact study authors and obtain necessary information. We assessed the quality of the evidence using the GRADE approach.

Main results

In total, we included 13 studies with 919 women. In 10 studies individual women were the unit of analysis and in three studies, individual breasts were the unit of analysis. Four out of 13 studies were funded by an agency with a commercial interest, two received charitable funding, and two were funded by government agencies.

Trials examined interventions including non-medical treatments: cabbage leaves (three studies), acupuncture (two studies), ultrasound (one study), acupressure (one study), scraping therapy (Gua Sha) (one study), cold breast-packs and electromechanical massage (one study), and medical treatments: serrapeptase (one study), protease (one study) and subcutaneous oxytocin (one study). The studies were small and used different comparisons with only single studies contributing data to outcomes of this review. We were unable to pool results in meta-analysis and only seven studies provided outcome data that could be included in data and analysis.

Non-medical

No differences were observed in the one study comparing acupuncture with usual care (advice and oxytocin spray) (risk ratio (RR) 0.50, 95% confidence interval (CI) 0.13 to 1.92; one study; 140 women) in terms of cessation of breastfeeding. However, women in the acupuncture group were less likely to develop an abscess (RR 0.20, 95% CI 0.04 to 1.01; one study; 210 women), had less severe symptoms on day five (RR 0.84, 95% CI 0.70 to 0.99), and had a lower rate of pyrexia (RR 0.82, 95% CI 0.72 to 0.94) than women in the usual care group.

In another study with 39 women comparing cabbage leaf extract with placebo, no differences were observed in breast pain (mean difference (MD) 0.40, 95% CI -0.67 to 1.47; low-quality evidence) or breast engorgement (MD 0.20, 95% CI -0.18 to 0.58; low-quality evidence). There was no difference between ultrasound and sham treatment in analgesic requirement (RR 0.98, 95% CI 0.63 to 1.51; one study; 45 women; low-quality evidence). A study comparing Gua-Sha therapy with hot packs and massage found a marked difference in breast engorgement (MD -2.42, 95% CI -2.98 to -1.86; one study; 54 women), breast pain (MD -2.01, 95% CI -2.60 to -1.42; one study; 54 women) and breast discomfort (MD -2.33, 95% CI -2.81 to -1.85; one study; 54 women) in favour of Gua-Sha therapy five minutes post-intervention, though both interventions significantly decreased breast temperature, engorgement, pain and discomfort at five and 30 minutes post-treatment.

Results from individual trials that could not be included in data analysis suggested that there were no differences between room temperature and chilled cabbage leaves and between chilled cabbage leaves and gel packs, with all interventions producing some relief. Intermittent hot/cold packs applied for 20 minutes twice a day were found to be more effective than acupressure (P < 0.001). Acupuncture did not improve maternal satisfaction with breastfeeding. In another study, women who received breast-shaped cold packs were more likely to experience a reduction in pain intensity than women who received usual care; however, the differences between groups at baseline, and the failure to observe randomisation, make this study at high risk of bias. One study found a decrease in breast temperature (P = 0.03) following electromechanical massage and pumping in comparison to manual methods; however, the high level of attrition and alternating method of sequence generation place this study at high risk of bias.

Medical

Women treated with protease complex were less likely to have no improvement in pain (RR 0.17, 95% CI 0.04 to 0.74; one study; 59 women) and swelling (RR 0.34, 95% CI 0.15 to 0.79; one study; 59 women) on the fourth day of treatment and less likely to experience no overall change in their symptoms or worsening of symptoms (RR 0.26, 95% CI 0.12 to 0.56). It should be noted that it is more than 40 years since the study was carried out, and we are not aware that this preparation is used in current practice. Subcutaneous oxytocin provided no relief at all in symptoms at three days (RR 3.13, 95% CI 0.68 to 14.44; one study; 45 women).

Serrapeptase was found to produce some relief in breast pain, induration and swelling, when compared to placebo, with a fewer number of women experiencing slight to no improvement in overall breast engorgement, swelling and breast pain.

Overall, the risk of bias of studies in the review is high. The overall quality as assessed using the GRADE approach was found to be low due to limitations in study design and the small number of women in the included studies, with only single studies providing data for analysis.

Authors' conclusions

Although some interventions such as hot/cold packs, Gua-Sha (scraping therapy), acupuncture, cabbage leaves and proteolytic enzymes may be promising for the treatment of breast engorgement during lactation, there is insufficient evidence from published trials on any intervention to justify widespread implementation. More robust research is urgently needed on the treatment of breast engorgement.

Résumé scientifique

Traitements de l'engorgement mammaire pendant l'allaitement

Contexte

L'engorgement mammaire est une affection douloureuse et désagréable qui concerne un grand nombre de femmes au début du post-partum. C'est une situation particulièrement perturbante alors que la jeune mère doit s'habituer aux demandes de son nouveau-né. L'engorgement mammaire peut empêcher la réussite de l'allaitement, entraîner un arrêt précoce de l'allaitement ; il est associé à des maladies plus graves, comme l'infection mammaire.

Objectifs

Identifier les meilleures formes de traitement pour les femmes présentant un engorgement mammaire.

Stratégie de recherche documentaire

Nous avons identifié des études à inclure dans le registre des essais cliniques du groupe Cochrane sur la grossesse et la naissance (février 2010).

Critères de sélection

Essais contrôlés randomisés et quasi-randomisés évaluant des traitements contre l'engorgement mammaire.

Recueil et analyse des données

Deux auteurs de l'analyse documentaire ont évalué l'éligibilité à l'inclusion et ont procédé à l'extraction des données.

Résultats principaux

Nous avons inclus huit études (744 femmes). Les essais portaient sur plusieurs traitements de l'engorgement mammaire : l'acupuncture (deux études), les feuilles de chou (deux études), les packs de gel froid (une étude), les traitements pharmacologiques (deux études) et les ultrasons (une étude). Pour plusieurs interventions (ultrasons, feuilles de chou et ocytocine), on ne disposait d'aucune preuve statistiquement significative d'une association de ces interventions avec une disparition plus rapide des symptômes, les femmes de ces études présentant une amélioration de la douleur et des autres symptômes dans le temps qu'elles aient ou non reçu le traitement actif. Dans une étude, on disposait de preuves indiquant que les femmes traitées par acupuncture présentaient une amélioration des symptômes dans les jours suivant le traitement supérieure à celle observée chez les femmes recevant les soins habituels ; on ne dispose cependant d'aucune preuve d'une différence entre les groupes à six jours. L'étude n'était pas d'une envergure suffisante pour détecter des différences significatives pour les autres critères de jugement, comme les abcès mammaires. Une étude portant sur un complexe de la protéase a rapporté des résultats en faveur des groupes bénéficiant de l'intervention, mais cette étude date de 40 ans et nous ignorons si cette préparation est encore utilisée actuellement. Une étude sur les packs de gel froid semble montrer que l'application de froid sur les seins n'a aucun effet délétère et peut être associé à des améliorations des symptômes, bien que les différences entre le groupe témoin et le groupe recevant les packs de gel froid avant le début du traitement rendent difficile l'interprétation des résultats.

Conclusions des auteurs

En dépit de l'intérêt de certaines interventions, on ne dispose pas de preuves suffisantes pour justifier une large application de l'une quelconque de ces interventions. Des recherches complémentaires sur des traitements de cette affection douloureuse et perturbante sont nécessaires.

アブストラクト

授乳中の乳房緊満に対する治療

背景

乳房緊満は疼痛を伴う状態で、産後早期に多くの女性にみられる。早期の離乳、乳頭亀裂、乳腺炎、および乳房膿瘍に至ることがある。乳房緊満についてさまざまな治療法が研究されているが、有効な介入に関するエビデンスはほとんどない。

目的

本稿はSnowdenらが2001年に発表し、2010年に更新されたシステマティックレビューの最新版である。今回の更新では、授乳中の女性の乳房緊満に対する最適な治療法について、新規の情報を探すことを目的とした。

検索戦略

Cochrane Pregnancy and Childbirth Group's Trials Registerを検索し(2015年6月30日)、得られた研究の参考文献リストを調べて、選択する研究を同定した。

選択基準

ランダム化および準ランダム化比較試験。

データ収集と分析

2名のレビュー著者がそれぞれ試験の適格性を評価し、データを抽出し、バイアスのリスクを評価した。試験で報告されたデータが不十分な場合は、試験著者に連絡して必要な情報を得るよう努めた。GRADE法を用いてエビデンスの質を評価した。

主な結果

合計919例の女性を対象とした13件の研究を選択した。10件の研究では女性を解析単位とし、3件では乳房を解析単位とした。13件中4件の研究は商業的関心のある機関から資金援助を、2件は慈善寄付を、2件は政府機関から資金援助を受けた。

試験では以下の介入について調べた。非内科的治療:キャベツの葉(3件の研究)、鍼(2件)、超音波(1件)、指圧(1件)、擦り療法(グアシャ)、(1件)、乳房の冷湿布と電気機械によるマッサージ(1件)。内科的治療: セラペプターゼ(1件)、プロテアーゼ(1件)、オキシトシンの皮下投与(1件)。研究は小規模で異なる比較が用いられており、本レビューのアウトカムに寄与したデータはそれぞれ単一の研究であった。メタアナリシスでは結果を統合できず、解析に寄与したアウトカムデータが得られたのは7件の研究のみであった。

非内科的治療

授乳中止について、鍼と通常治療(助言とオキシトシンスプレー)を比較した1件の研究では差がみられなかった(リスク比(RR)0.50、95% 信頼区間(CI)0.13 ~ 1.92、1件の研究、140例)。しかし、鍼群の女性は通常治療群の女性よりも膿瘍の発症が少なく(RR 0.20、95% CI 0.04 ~1.01、1件の研究、210例)、5日目の症状が軽く(RR 0.84、95% CI 0.70 ~ 0.99)、発熱率が低かった(RR 0.82、95% CI 0.72 ~ 0.94)。

39例を対象にキャベツの葉の抽出物とプラセボを比較した研究では、以下について差はなかった。乳房痛:平均差(MD)0.40、95% CI -0.67 ~ 1.47、エビデンスの質は低い。乳房緊満: MD 0.20、95% CI -0.18 ~ 0.58、エビデンスの質は低い。鎮痛剤の必要性について、超音波と偽治療に差はなかった(RR 0.98、95% CI 0.63 ~1.51、1件の研究、45例、エビデンスの質は低い)。グアシャ療法と、温湿布とマッサージの併用を比較した研究において、介入後5分の時点ではグアシャ療法に利益があり、乳房緊満(MD -2.42、95% CI -2.98 ~ -1.86、1件の研究、54例)、乳房痛(MD -2.01、95% CI -2.60 ~ -1.42、1件の研究、54例)、および胸部不快感(MD -2.33、95% CI -2.81 ~ -1.85、1件の研究、54例)で顕著な差がみられたが、治療後5分および30分の時点では両介入で乳房の温度、腫脹、疼痛、および不快感が大幅に低下した。

データ解析に寄与しなかった試験結果により、常温と冷蔵のキャベツの葉や、冷蔵とゲル状パックのキャベツの葉では、緩和目的のあらゆる介入において差はないことが示唆された。1日2回20分の間欠的な温/冷湿布は指圧よりも有効なことがわかった(P < 0.001)。鍼は、授乳に対する母親の満足度を改善しなかった。別の研究では、乳房状の冷湿布をした女性で通常治療を受けた女性よりも疼痛強度が低下したが、ベースラインの群間差やランダム化の欠如により、この研究のバイアスのリスクは高かった。1件の研究では、電動のマッサージやポンプの使用後は手動よりも乳房の温度が低下したが(P = 0.03)、症例減少が多く、交互に繰り返すシーケンス生成法により、この研究のバイアスのリスクは高かった。

内科的治療

プロテアーゼ複合体を投与した女性では、治療の4日目で疼痛(RR 0.17、95% CI 0.04 ~ 0.74、1件の研究、59例)や腫れ(RR 0.34、95% CI 0.15 ~ 0.79、1件の研究、59例)に改善がみられないということはなかったが、全般的な症状の変化や悪化がみられないこともなかった(RR 0.26、95% CI 0.12 ~ 0.56)。注目すべきはこの研究が実施されてから40年以上経つことで、この製剤が現在の診療に使われているという認識はない。オキシトシンの皮下投与は3日の時点で症状をまったく緩和しなかった(RR 3.13、95% CI 0.68 ~ 14.44、1件の研究、45例)。

セラペプターゼはプラセボと比較して乳房の疼痛、硬結、腫れをやや緩和し、乳房緊満、腫れ、乳房痛の全般的な改善が軽度、もしくはまったく改善しない女性はわずかであった。

全般的に、本レビューの研究におけるバイアスのリスクは高かった。GRADE法で評価した全般的な質が低いのは、研究デザインの限界、研究の症例数が少ない、解析に寄与したデータが単一の研究のみによることが原因である。

著者の結論

温/冷湿布、グアシャ(擦り療法)、鍼、キャベツの葉、蛋白分解酵素など、授乳中の乳房緊満の治療に有望な可能性のある介入もあるが、いずれかの介入について広範な実施の妥当性を示すには、発表済み試験のエビデンスが不十分である。乳房緊満の治療について、より確固たる研究が早急に必要である。

Plain language summary

Treatment for breast engorgement (overfull, hard, painful breasts) in breastfeeding women

Review question

What are the best forms of treatment for engorged breasts in breastfeeding women?

Background

Breast engorgement is the overfilling of breasts with milk leading to swollen, hard and painful breasts. Many women experience this during the first few days after giving birth, although it can occur later. It is more common when the timing of breastfeeding is restricted or the baby has difficulty sucking or the mother is separated from her newborn. This leads to the breasts not being emptied properly. Breast engorgement may make it difficult for women to breastfeed. It may lead to complications such as inflammation of the breast, infection and sore/cracked nipples. So far, consistent evidence for effective forms of treatment is lacking.

Study characteristics

We searched for trials on any treatments for breast engorgement in breastfeeding women. We looked at 13 trials including 919 breastfeeding women who had engorged breasts. The trials looked at treatments including acupuncture, acupressure, cabbage leaves, cold packs, medication, massage and ultrasound. Four of the studies were funded by an agency with a commercial interest in the results of the studies, two received charitable funding and two were funded by government agencies. The other five did not declare the source of funding.

Results

One study comparing acupuncture with usual care (advice and oxytocin spray) found no difference in terms of stopping breastfeeding. However, women in the acupuncture group were less likely to develop an abscess, had less severe symptoms on day five and had a lower rate of fever than women in the usual care group. Three trials looking at cabbage leaves showed no difference between room temperature and chilled cabbage leaves, between chilled cabbage leaves and gel packs and between cabbage cream and the inactive cream; however, all forms of treatment provided some relief. Hot/cold packs were found to be more effective than acupressure. Gua Sha scraping therapy was found to be more effective than hot packs and massage in reducing symptoms of breast engorgement, though both forms of treatment decreased breast temperature, engorgement, pain and discomfort at five and 30 minutes after treatment. A study on ultrasound therapy had the same, minimal effect as the fake ultrasound, whereas oxytocin injections in another study provided no relief at all. When breast-shaped cold gel packs were compared with routine care, women who used gel packs seemed to have less pain; however, the study was of very low quality making the results unreliable.

Quality of evidence

The quality of evidence was low due to the small number of participants in the included studies and limited number of studies looking at the same outcomes. More robust research is urgently needed on the treatment of breast engorgement.

Résumé simplifié

Traitement de l'engorgement mammaire chez les femmes allaitantes

Un engorgement mammaire se produit lorsque les seins sont trop remplis de lait, qu'ils gonflent, durcissent et sont douloureux. Un grand nombre de femmes sont confrontées à ce problème, généralement les premiers jours suivant l'accouchement, mais également à un stade ultérieur. C'est une situation particulièrement perturbante alors que la jeune mère doit s'habituer aux demandes de son nouveau-né. L'engorgement mammaire peut être le signe de l'échec du début de l'allaitement et décourager la mère. Il peut engendrer des maladies graves, comme l'infection mammaire. L'objectif de cette analyse documentaire est de passer en revue les traitements utilisés pour soulager les symptômes d'un engorgement mammaire. Nous avons inclus huit essais contrôlés randomisés impliquant au total 744 femmes. Les études portaient sur différents traitements de l'engorgement mammaire, notamment l'acupuncture, l'application de feuilles de chou sur les seins, les packs de gel froid, les traitements pharmacologiques et les ultrasons. Pour certaines interventions (ultrasons, feuilles de chou et ocytocine), on ne disposait d'aucune preuve solide d'une disparition rapide des symptômes, les femmes de ces études présentant une amélioration de la douleur et des autres symptômes dans le temps qu'elles aient ou non reçu le traitement actif. Dans une étude, on disposait de preuves indiquant que les femmes traitées par acupuncture présentaient une amélioration des symptômes dans les jours suivant le traitement supérieure à celle observée chez les femmes recevant les soins habituels ; on ne dispose cependant d'aucune preuve d'une différence entre les groupes à six jours. L'étude n'était pas d'une envergure suffisante pour détecter des différences significatives pour les autres critères de jugement, comme les abcès mammaires. Une étude sur les packs de gel froid semble montrer que l'application de froid sur les seins n'a aucun effet délétère et peut être associé à des améliorations des symptômes, bien que les différences entre le groupe témoin et le groupe recevant les packs de gel froid avant le début du traitement laissaient prévoir une interprétation difficile des résultats. Cette analyse documentaire permet de conclure qu'en dépit de l'intérêt de certaines interventions, on ne dispose pas de preuves suffisantes émanant d'essais bien conçus pour justifier une large utilisation de l'intervention. Des recherches complémentaires sur des traitements de cette affection douloureuse et perturbante sont nécessaires.

Notes de traduction

Translated by: French Cochrane Centre

Translation supported by: Ministère du Travail, de l'Emploi et de la Santé Français

Laički sažetak

Liječenje zastojne dojke (dojka prepunjena mlijekom) kod dojilja

Zastojne dojke su dojke prepunjene mlijekom uslijed čega postaju otečene, tvrde i bolne. Veliki broj žena ima zastojne dojke, obično u prvim danima po porodu, ali se može pojaviti i kasnije. U vrijeme kada se žene nose sa zahtjevima novog djeteta, ovo stanje može biti posebno stresno. Zastojne dojke mogu dovesti do neuspješnog započinjanja dojenja, odustajanja od dojenja, ili do ozbiljne bolesti poput infekcije dojke. Cilj ovog sustavnog pregleda je bio proučiti načine liječenja zastojnih dojki. U sustavni pregled je uključeno osam randomiziranih kontroliranih studija sa 774 žene. Istraživanja su proučavala razne metode liječenja zastojnih dojki uključujući akupunkturu, listove kupusa, hladne obloge, farmakološke terapije i ultrazvuk. Za neke od intervencija (ultrazvuk, listovi kupusa i oksitocin) nije bilo jakih dokaza da je intervencija pomogla u bržem povlačenju simptoma jer su žene u ovim istraživanjima pokazale smanjenje boli i poboljšanje drugih simptoma tijekom vremena bez obzira jesu li dobivale aktivni lijek ili ne. U jednom istraživanju je bilo dokaza da je kod žena koje su bile na akupunkturi u odnosu na žene koje su dobivale rutinsku skrb došlo do poboljšanja simptoma u danima nakon terapije, ali ne i nakon šest dana. Međutim ovo istraživanje nije bilo dovoljno veliko da bi se mogle uočiti značajne razlike u drugim ishodima poput apscesa dojke. Jedno istraživanje, koje je proučavalo hladne obloge, pronašlo je da primjena hladnih obloga ne šteti te je možda povezana s poboljšanjem simptoma, ali razlike između kontrolne i terapijske skupine prije započinjanja liječenja su otežale tumačenje rezultata. Opći zaključak ovog sustavnog pregleda jest da, iako su neke intervencije obećavajuće, nema dovoljno dokaza iz kvalitetnih studija o ijednoj intervenciji koja bi opravdala njezinu široku primjenu. Potrebno je više istraživanja provesti o liječenju ovog bolnog i stresnog stanja.

Bilješke prijevoda

Hrvatski Cochrane
Prevela: Irena Zakarija-Grković
Ovaj sažetak preveden je u okviru volonterskog projekta prevođenja Cochrane sažetaka. Uključite se u projekt i pomozite nam u prevođenju brojnih preostalih Cochrane sažetaka koji su još uvijek dostupni samo na engleskom jeziku. Kontakt: cochrane_croatia@mefst.hr

Резюме на простом языке

Лечение нагрубания молочных желёз (переполненные, твердые, болезненные молочные железы) у кормящих женщин

Вопрос обзора

Какие формы лечения нагрубания молочных желез у кормящих женщин являются лучшими?

Актуальность

Нагрубание молочных желез - это переполнение их молоком, приводящее к распуханию, отвердению и болезненности молочных желез. Многие женщины испытывают такое в первые дни после родов, хотя это может случаться и на более поздних сроках. Чаще всего это возникает, когда время кормления ограничено, или ребенок имеет трудности в сосании, или мать отделена от ее новорожденного. Это ведет к тому, что молочные железы не опустошаются до конца. Нагрубание молочных желез может затруднить женщинам грудное вскармливание. Это может приводить к таким осложнениям, как воспаление молочной железы, инфекция и изъязвление или трещины сосков. До сих пор не хватает основательных доказательств в отношении эффективных форм лечения.

Характеристика исследований

Мы провели поиск испытаний, оценивающих любые способы лечения нагрубания молочных желёз у кормящих женщин. Мы нашли 13 испытаний, включающих 919 кормящих женщин с нагрубанием молочных желёз. Эти испытания рассматривали варианты лечения, включая иглоукалывание, точечный массаж, капустные листья, холодные компрессы, прием лекарств, массаж и ультразвук. Четыре исследования были спонсированы организациями, коммерчески заинтересованными в результатах, два - получили благотворительное финансирование и два - получали поддержку государственных организаций. Остальные пять не назвали источник финансирования.

Результаты

Одно исследование, сравнивавшее иглоукалывание с обычным уходом (совет и окситоциновый спрей) не обнаружило разницы в отношении прекращения кормления грудью. Однако, женщины в группе иглоукалывания имели меньшую вероятность развития абсцесса, менее тяжелые симптомы на пятый день и меньшую частоту лихорадки в сравнении с женщинами из группы обычного ухода. Три испытания, рассматривавшие капустные листья, показали отсутствие разницы между капустными листьями комнатной температуры и охлажденными, между охлажденными капустными листьями и пакетами с гелем и между капустным кремом и неактивным кремом; однако все виды лечения принесли некоторое облегчение. Горячие/холодные компрессы оказались более эффективными, чем точечный массаж. Gua Sha терапия скребками, как было обнаружено, была более эффективна, чем горячие компрессы и массаж в уменьшении симптомов нагрубания молочных желёз, хотя обе формы лечения снижали температуру молочных желёз, нагрубание, боль и дискомфорт через пять и 30 минут после лечения. Исследование ультразвуковой терапии показало такой же минимальный эффект, как и при имитации ультразвука, тогда как инъекции окситоцина в другом исследовании совсем не принесли облегчения. Когда холодные гелевые пакеты по форме груди сравнивали с обычным уходом, женщины, использовавшие пакеты, как казалось, испытывали меньшую боль; однако, исследование было очень низкого качества и результаты его ненадёжны.

Качество доказательств

Качество доказательств было низким из-за малого числа участников во включенных исследованиях и ограниченного числа исследований, рассматривающих одинаковые исходы. Остро требуются более надежные исследования по лечению нагрубания молочных желёз.

Заметки по переводу

Перевод: Змиевская Екатерина Анатольевна. Редактирование: Зиганшина Лилия Евгеньевна. Координация проекта по переводу на русский язык: Cochrane Russia - Кокрейн Россия (филиал Северного Кокрейновского Центра на базе Казанского федерального университета). По вопросам, связанным с этим переводом, пожалуйста, обращайтесь к нам по адресу: cochrane.russia.kpfu@gmail.com; cochranerussia@kpfu.ru

Streszczenie prostym językiem

Leczenie obrzęku piersi (przepełnionych, twardych i bolesnych piersi) u kobiet karmiących piersią

Pytanie przeglądu

Jaka jest najlepsza metoda leczenia obrzęku piersi u kobiet karmiących?

Wprowadzenie

Obrzęk piersi to przepełnienie ich mlekiem, co prowadzi do ich obrzmienia, twardości i bolesności. Wiele kobiet doświadcza tego podczas pierwszych kilku dni po porodzie, choć taki stan może występować również później. Problem ten jest częstszy, gdy czas karmienia jest ograniczony lub dziecko ma trudności ze ssaniem, lub też gdy matka jest oddzielona od noworodka. To wszystko powoduje, że piersi nie są dostatecznie opróżniane. Obrzęk piersi może prowadzić do trudności w karmieniu piersią. Ponadto, może też skutkować powikłaniami takimi jak zapalenie piersi, zapalenie i ból/pękanie brodawek. Jak dotąd brakuje spójnych danych o skutecznych metodach leczenia.

Charakterystyka badania

Poszukiwaliśmy badań dotyczących jakiejkolwiek metody leczenia obrzęku piersi u kobiet karmiących. Przeanalizowaliśmy 13 badań, obejmujących 919 kobiet karmiących z obrzękiem piersi. Badania dotyczyły metod leczenia takich jak: akupunktura, akupresura, stosowanie liści kapusty, zimnych okładów, leków, masażu oraz ultradźwięków. Cztery badania były finansowane przez podmioty zainteresowane komercyjnym wykorzystaniem wyników badań, dwa badania były finansowane z funduszy charytatywnych oraz dwa badania przez podmioty rządowe. W pozostałych pięciu badaniach nie podano źródła finansowania.

Wyniki

W jednym z badań, w którym porównano akupunkturę ze standardową opieką (porady i oksytocyna w sprayu) nie wykazano różnic w odniesieniu do zaprzestania laktacji. Jednakże, u kobiet w grupie stosującej akupunkturę mniejsze było prawdopodobieństwo rozwoju ropnia, mniej nasilone były objawy w 5. dniu oraz rzadziej występowała gorączka, w porównaniu do kobiet z grupy otrzymującej standardową opiekę. W trzech badaniach dotyczących liści kapusty nie wykazano różnicy pomiędzy stosowaniem liści w temperaturze pokojowej a schłodzonymi, pomiędzy schłodzonymi liśćmi kapusty a żelowymi okładami oraz między kremami z wyciągiem z kapusty a kremami bez aktywnego składnika. Jednakże wszystkie metody leczenia przynosiły ulgę. Ciepłe/zimne okłady okazały się bardziej skuteczne niż akupresura. Gua Sha, (technika medycyny chińskiej, polegająca na działaniu na skórę w taki sposób, aby wywołać jej lokalne zaczerwienie lub nawet wybroczyny - przyp. tłum.) okazała się bardziej skuteczna, w łagodzeniu objawów obrzęku piersi, niż gorące okłady i masaż, chociaż obie formy leczenia wiązały się z obniżeniem temperatury piersi, zmniejszeniem nasilenia obrzęku, zmniejszeniem natężenia bólu i dyskomfortu po pięciu i po 30 minutach po zabiegu. W badaniach dotyczących terapii ultradźwiękami wykazano podobny, minimalny efekt w porównaniu do pozorowanych ultradźwięków, natomiast, w innym badaniu, podawanie oksytocyny w zastrzykach nie przynosiło ulgi w ogóle. Wydaje się, że stosowanie żelowych okładów chłodzących dostosowanych do kształtu piersi, w porównaniu z rutynową opieką, przynosiło zmniejszenie bólu, jednakże bardzo niska jakość badania podaje w wątpliwość wiarygodność wyników.

Jakość danych

Jakość danych była niska, ze względu na małą liczbę uczestniczek włączonych do badań oraz ograniczoną liczbę badań oceniających te same wyniki. Pilne potrzebne są dalsze, dobrze zaplanowane badania, dotyczące leczenia obrzęku piersi.

Uwagi do tłumaczenia

Tłumaczenie Magdalena Koperny Redakcja Joanna Zając

Ringkasan bahasa mudah

Rawatan untuk bengkak payudara (berisi lebih, keras, sakit payudara) di kalangan wanita menyusui bayi

Soalan ulasan

Apakah rawatan-rawatan yang terbaik untuk bengkak payudara di kalangan ibu ynag menyusui bayi?.

Latarbelakang

Bengkak payu dara adalah payudara yang kelebihan produksi susu sehingga menyebabkan ia menjadi bengkak, keras dan menyakitkan. Ramai wanita mengalami masalah ini dalam beberapa hari pertama selepas melahirkan anak, walaupun ia boleh berlaku kemudian. Ia adalah lebih lazim apabila masa penyusuan adalah terhad atau bayi mempunyai kesukaran menghisap atau ibu dipisahkan dari bayi yang baru lahir. Ini mengakibatkan kepada payudara tidak dikosongkan dengan betul. Bengkak payudara boleh menyukarkan wanita untuk menyusukan bayi. Ia boleh menyebabkan komplikasi seperti radang payudara, jangkitan dan puting sakit / retak. Setakat ini, bukti yang konsistent agak kurang untuk menyokong berkesanan rawatan.

Ciri-ciri kajian

Kami mencari kajian mengenai sebarang rawatan untuk bengkak payudara di kalangan ibu yang menyusui bayi. Kami meneliti 13 kajian yan meliputi 919 wanita yang menyusui yang mengalami bengkak payudara. Kajian kajian berkenaan mengkaji rawatan termasuk akupunktur, akutekanan, daun kubis, pek sejuk, ubat, urut dan ultrasound. Empat daripada kajian telah dibiayai oleh sebuah agensi yang mempunyai kepentingan komersial dalam keputusan kajian, dua menerima pembiayaan kebajikan dan dua dibiayai oleh agensi-agensi kerajaan. Lima yang lain tidak mengisytiharkan sumber pembiayaan.

Keputusan

Satu kajian membandingkan akupunktur dengan rawatan biasa (nasihat dan semburan oxytocin) mendapati tiada perbezaan dari segi pemberhentian penyusuan. Walau bagaimanapun, wanita dalam kumpulan akupunktur didapati kurang berkemungkinan untuk mendapati nanah, mempunyai kurang simptom yang teruk pada hari ke lima (selepas bersalin) dan rendah kadar mendapat demam berbanding dengan wanita dalam kumpulan penjagaan biasa. Tiga kajian yang mengkaji daun kubis menunjukkan tiada perbezaan antara suhu bilik dan daun kubis sejuk, antara daun kubis sejuk dan pek gel dan antara krim kubis dan krim aktif; Walau bagaimanapun, semua bentuk rawatan yang disediakan memberi sedikit kelegaan. Pek panas / sejuk didapati lebih berkesan daripada akutekanan. Gua Sha terapi mengikis telah didapati lebih berkesan daripada pek panas dan urut dalam mengurangkan tanda-tanda kebengkakkan payu dara, walaupun kedua-dua bentuk rawatan menurun suhu payudara, kebengkakkan, sakit dan rasa tidak selesa pada lima minit dan 30 minit selepas rawatan. Kajian mengenai terapi ultrasound mempunyai kesan yang sama dan minimal seperti ultrasound palsu, manakala suntikan oxytocin pula dalam kajian yang lain tidak memberi kelegaan langsung Apabila pek gel berbentuk payudara sejuk dibandingkan dengan penjagaan rutin, wanita yang menggunakan pek gel seolah-olah mempunyai kesakitan yang kurang; Walau bagaimanapun, kajian ini adalah berkualiti sangat rendah menyebabkan keputusan yang tidak boleh dipercayai.

Kualiti bukti

Kualiti bukti adalah rendah disebabkan bilangan kecil para peserta dalam kajian yang dilibatkan dan bilangan kajian yang terhad memerhatikan hasil yang sama. Lebih banyak penyelidikan yang mantap amat diperlukan untuk rawatan kebengkakkan payu dara.

Catatan terjemahan

Diterjemahkan oleh Nila Pillai (Penang Medical College) Disunting oleh Sharifah Halimah Jaafar (Regency Specialist Hospital Sdn Bhd JB) Untuk sebarang pertanyaan mengenai terjemahan ini sila hubungi nila@pmc.edu.my.

Laienverständliche Zusammenfassung

Behandlungsmethoden bei Milchstau (übervolle, harte, schmerzhafte Brust) bei stillenden Müttern

Fragestellung

Welche sind die besten Behandlungsmethoden für Stillende bei Milchstau?

Hintergrund

Ein Milchstau entsteht durch einen Überschuss an Milch, der zu geschwollenen, harten und schmerzenden Brüsten führt. Bei vielen Frauen kommt es in den ersten Tagen nach der Geburt zu einem Milchstau. Er kann aber auch zu einem späteren Zeitpunkt entstehen. Milchstau tritt häufiger auf, wenn die Stillzeiten vorgegeben werden, das Neugeborene Schwierigkeiten hat zu saugen oder Mutter und Kind getrennt voneinander untergebracht sind. Diese Bedingungen führen dazu, dass die Brüste nicht vollständig entleert werden. Ein Milchstau kann das Stillen erschweren und zudem zu Komplikationen wie Brustentzündung, Infektionen oder wunde und rissige Brustwarzen führen. Bislang liegt keine ausreichende Evidenz dafür vor, welche Behandlungsmethoden wirksam sind.

Studienmerkmale

Wir suchten nach Studien, die jede mögliche Art von Behandlung bei Milchstau bei Stillenden untersuchten. Wir haben 13 Studien, mit insgesamt 919 Stillenden mit Milchstau, betrachtet. Die Studien untersuchten unter anderem folgende Behandlungsmethoden: Akupunktur, Akupressur, Kohlblätterauflagen, Kältekompressen, Medikation, Massagen und Ultraschall. Von diesen Studien wurden vier von Institutionen finanziert, denen ein kommerzielles Interesse an den Ergebnissen unterstellt werden kann. Zwei Studien hatten eine finanzielle Unterstützung von gemeinnützigen Organisationen und zwei von staatlichen Stellen. Die übrigen fünf Studien haben die Finanzierung nicht offengelegt.

Ergebnisse

Eine Studie hat Akupunktur mit herkömmlicher Behandlung (Beratung und Oxytocin-Spray) verglichen und konnte keine Unterschiede bezüglich des Abstillens feststellen. In der Akupunktur-Gruppe war jedoch die Wahrscheinlichkeit geringer, dass Frauen unter einem Abszess (Eiteransammlung) litten. Sie hatten zudem am fünften Tag nach der Behandlung weniger schwerwiegende Symptome und auch die Rate an Frauen mit Fieber war kleiner als bei Frauen mit der herkömmlichen Behandlung. Drei Studien untersuchten die Behandlung mit Kohlwickeln. Es zeigten sich keine Unterschiede zwischen der Behandlung mit gekühlten und nicht gekühlten Kohlblättern, zwischen gekühlten Kohlblättern und Kältekompressen und zwischen einer Creme aus Kohlblätterextrakt und einer Creme ohne Wirkung (Placebo-Creme). Alle Behandlungsmethoden brachten jedoch etwas Linderung. Kalte/Warme Kompressen zeigten eine bessere Wirkung als eine Behandlung mit Akupressur. Die Gua-Sha-Behandlung (Schaben auf der eingeölten Haut mit einem Gegenstand mit abgerundeter Kante) stellte sich zur Linderung der Symptome von Milchstau als wirksamer heraus als die Behandlung mit Wärmekompressen und Massagen; wobei beide Behandlungsmethoden die Brusttemperatur, den Milchstau sowie Schmerzen und Beschwerden nach 5 bis 30 Minuten nach der Behandlung senkten. In einer Studie zur Ultraschalltherapie hatten sowohl Behandlungen mit Ultraschall als auch Behandlungen mit Schein-Ultraschall (ohne Ultraschallwellen) lediglich eine geringe Wirkung. Die Oxytocin-Injektion, die in einer weiteren Studie untersucht wurde, brachte hingegen keine Erleichterung. Kältekompressen in Form einer Brust wiesen im Vergleich zur herkömmlichen Behandlung eine bessere schmerzlindernde Wirkung auf. Die Studie war jedoch von sehr niedriger Qualität, sodass das Ergebnis unzuverlässig ist.

Qualität der Evidenz

Die Qualität der Evidenz war aufgrund der geringen Teilnehmerinnenzahl sowie der begrenzten Anzahl von Studien, die dieselben Endpunkte überprüften, niedrig. Zuverlässigere Forschung zu den Behandlungsmethoden bei Milchstau ist dringend erforderlich.

Anmerkungen zur Übersetzung

A. Lintner, C. Loytved, freigegeben durch Cochrane Schweiz

平易な要約

授乳中の女性における乳房緊満(母乳分泌過多、乳房の硬化や痛み)に対する治療

レビューの論点

授乳中の女性における乳房緊満の最適な治療法は?

背景

乳房緊満は母乳分泌が多すぎることにより、乳房の腫れ、硬化、痛みを生じる。多くの女性で産後数日以内に生じるが、後から生じる場合もある。授乳時間が制限されたり、乳児の吸乳が困難であったり、母親が新生児から隔離されたりすると、乳房緊満がより多くみられる。こうした状況では、乳房がきちんと空にならない。乳房緊満は女性にとって授乳を困難にする場合がある。乳房の炎症、感染、乳頭の痛みや亀裂などの合併症を起こすことがある。これまで、有効な治療法に関する一貫したエビデンスはない。

試験の特性

授乳中の女性における乳房緊満の治療に関する試験を探した。乳房緊満の女性919例を対象とした13件の研究について調べた。試験では鍼、指圧、キャベツの葉、冷湿布、投薬、マッサージ、および超音波による治療について調べた。4件の研究は結果に商業的関心のある機関から資金援助を、2件は慈善寄付を、2件は政府機関から資金援助を受けた。5件については資金源が公表されていなかった。

結果

授乳中止について、鍼と通常治療(助言とオキシトシンスプレー)を比較した1件の研究では差がみられなかった。しかし、鍼群の女性は通常治療群の女性よりも膿瘍の発症が少なく、5日目の症状が軽く、発熱率が低かった。キャベツの葉について調べた3件の試験では、常温と冷蔵のキャベツの葉、冷蔵とゲル状パックのキャベツの葉、キャベツクリームと不活性クリームに差はないことが示唆されたが、すべての治療法でやや緩和がみられた。温/冷湿布は指圧よりも有効なことがわかった。グアシャ(擦り療法)は温湿布とマッサージの併用よりも乳房緊満の症状の減少には有効だが、治療後5分および30分の時点では2つの治療法で乳房の温度、腫脹、痛み、および不快感が低下した。超音波療法に関する1件の研究では超音波と偽超音波に同等のわずかな効果がみられたが、別の研究ではオキシトシン注射による緩和はまったくみられなかった。乳房状の冷湿布をした女性では通常治療を受けた女性よりも痛みが減少したようだったが、この研究の質は極めて低いため結果に信頼性がない。

エビデンスの質

全般的なエビデンスの質が低いのは、研究の症例数が少ないこと、同一のアウトカムを調べた研究数が少ないことによる。乳房緊満の治療について、より確固たる研究が早急に必要である。

訳注

《実施組織》厚生労働省「「統合医療」に係る情報発信等推進事業」(eJIM:http://www.ejim.ncgg.go.jp/)[2018.2.28]
《注意》この日本語訳は、臨床医、疫学研究者などによる翻訳のチェックを受けて公開していますが、訳語の間違いなどお気づきの点がございましたら、eJIM事務局までご連絡ください。なお、2013年6月からコクラン・ライブラリーのNew review, Updated reviewとも日単位で更新されています。eJIMでは最新版の日本語訳を掲載するよう努めておりますが、タイム・ラグが生じている場合もあります。ご利用に際しては、最新版(英語版)の内容をご確認ください。 
CD006946 Pub3

Summary of findings(Explanation)

Summary of findings for the main comparison. Cabbage cream for breast engorgement during lactation
  1. 1 The number of participants was even smaller than the pre-determined sample size.
    2 Limitations in study design due to a significant imbalance in primiparas at baseline (high risk of bias for other bias).

Cabbage cream for breast engorgement during lactation

Patient or population: women with breast engorgement during lactation
Settings: Royal Darwin and Darwin Private Hospital, Australia
Intervention: cabbage cream

Comparison: placebo

OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
No of participants
(studies)
Quality of the evidence
(GRADE)
Comments
Assumed riskCorresponding risk
Control Cabbage cream
Breast pain
Bourbonaise pain scale
 The mean breast pain in the intervention groups was
0.4 higher
(0.67 lower to 1.47 higher)
 39
(1 study)

⊕⊕⊝⊝

low 1,2

Higher score indicates more pain - Bourbonaise pain scale ranks pain on a scale from 0 to 10, with 0 representing no pain and 10 representing excruciating pain.
Breast induration/hardness     This outcome was not reported in the trial.
Breast swelling     This outcome was not reported in the trial.
Breast engorgement
Hill and Humenich Breast engorgement scale
Follow-up: mean 4 days
 The mean engorgement in the intervention groups was
0.2 higher
(0.18 lower to 0.58 higher)
 39
(1 study)

⊕⊕⊝⊝

low 1,2

Higher score indicates more engorgement - Hill and Humenich Breast engorgement scale ranks engorgement on a scale from 0 to 6, with 0 representing soft, no change in breasts and 6 representing very firm, very tender.
Analgesic requirement     This outcome was not reported in the trial.
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval
GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

Background

In recognition of the importance of breastfeeding for maternal and infant well-being, and for society at large, the World Health Organization recommends that all babies should be exclusively breastfed for the first six months of life and then continue to receive breast milk, along with appropriate complementary foods, up to two years of age or beyond (WHO 2003). Despite this, less than 3% of women breastfeed their infants for 24 months (Carletti 2011; Hure 2013; Liu 2013). One of the most common factors associated with premature cessation of breastfeeding is difficulty with lactation (Odom 2013), including breast engorgement (Hauck 2011).

Description of the condition

Breast engorgement is the pathological overfilling of the breasts with milk, characterised by hard, painful, tight breasts and difficulty breastfeeding. It is usually due to compromised milk removal, either from restrictive feeding practices and/or ineffective sucking, or less commonly overproduction of milk. Augmentation mammoplasty (surgical enlargement of breasts) may also predispose to engorgement (Acarturk 2005). It should be differentiated from normal breast fullness, often called physiological breast engorgement (Nikodem 1993), occurring between day two to three postpartum, in which secretory activation of the breast is triggered by the delivery of the placenta (progesterone withdrawal) and subsequent rise in prolactin levels (Hale 2007). Increased milk production and interstitial tissue oedema ensue resulting in visibly larger, warmer and slightly uncomfortable breasts. In women with normal breast fullness, milk flow from the breast is not hindered and with frequent, efficient breastfeeding, discomfort resolves within a few days.

Breast engorgement, on the other hand, is a distressing and debilitating condition affecting between 15% and 50% of women (Hill 1994). Prevalence may be even higher depending on the definition used. Where engorgement was described as part of an inflammatory process (any mixture of erythema, pain, pyrexia, breast tension and resistance in breast tissue), 75% of women in a Swedish study experienced symptoms within eight weeks postpartum (Kvist 2004). Some level of breast tenderness during the first five days after birth was experienced by 72% of women in a study by Hill and Humenick. Engorgement symptoms occur most commonly between the second and fifth days postpartum (Hill 1994; Roberts 1995a), peaking at day five (Hill 1994), but may occur as late as day 14 (Humenick 1994), and are usually diffuse, bilateral and may be associated with a low-grade fever. Complications are common and include sore/damaged nipples, mastitis, abscess formation, decreased milk supply (Giugliani 2004), premature introduction of breast milk substitutes, and premature cessation of breastfeeding (Mass 2004). Difficulty in feeding the baby occurs in up to 82% of mothers with breast engorgement (Roberts 1995a).

Description of the intervention

Many interventions for the treatment of breast engorgement have been suggested in the past. Some treatments have been abandoned, such as mechanical compression (binding) of the breast, complete manual emptying of the breast, fluid restriction, the use of diuretics, oestrogens and bromocriptine, due to safety concerns. Others, such as some anti-inflammatory medications (bromelain, serrapeptase) have been tested on small sample sizes only, with no long-term safety data, and hence have not been widely accepted. Oxytocin, due to its role in inducing the milk-ejection reflex, has also been proposed as an efficacious agent for the relief of postpartum breast engorgement. Other modalities, such as ultrasound therapy, acupuncture and acupressure have also been explored. A popular form of treatment of breast engorgement is the application of cabbage leaves. Even though no active pharmacological substance in cabbage leaves has been identified in the literature, its convenient shape, low cost, wide availability and purportedly soothing effect make it a sought after treatment. Reverse pressure softening, a technique that uses gentle positive pressure with the finger-tips to soften the areola, has been shown to improve attachment of the infant to the breast during engorgement (Cotterman 2004), hence making it a potential tool for the treatment of breast engorgement, but relevant outcomes have not been tested in a controlled setting.

Current recommendations for the treatment of breast engorgement include various measures aimed at emptying the breast sufficiently to alleviate discomfort, facilitate breastfeeding and prevent complications. These include applying moist heat to the breast prior to feeding to aid oxytocin uptake, frequent feeding, softening the areola prior to attachment, correct positioning and attachment of the baby to the breast during breastfeeding (Mass 2004), gentle massage during feeding, and applying cold compresses after feeding (Core Curriculum 2013), along with analgesics (e.g. paracetamol) and anti-inflammatory medication (e.g. ibuprofen), if needed (ABM 2009). If breastfeeding is not possible, hand-expressing or pumping milk to comfort is recommended, along with other symptomatic measures.

In some countries, such as Sweden, oxytocin spray is routinely used in an attempt to enhance drainage of engorged breasts. A postal survey of all 57 breastfeeding clinics in Sweden, revealed that oxytocin spray, unrefined cotton wool (as a comfort measure) and acupuncture were used by 87%, 72% and 56% of responding clinics, respectively, for the treatment of breast inflammatory conditions (Kvist 2004). In other countries, such as Taiwan, cold therapies for breast engorgement are discouraged during the month following delivery. Instead, milk expression after the application of hot packs is widely used, as are traditional Chinese therapies.

How the intervention might work

Ideally, treatment of breast engorgement should: 1) provide rapid relief of breast pain; 2) enable successful attachment of the baby to the breast; 3) facilitate efficient drainage of milk from the breasts; and 4) prevent known complications such as mastitis and breast abscess. Optimal treatment should rapidly result in relatively soft, non-tender breasts from which the mother can easily and successfully feed her infant. Numerous treatments have been studied in an attempt to achieve these goals. The interventions studied in this review are based on the following assumptions:

  1. administration of exogenous oxytocin: release of endogenous oxytocin, from the posterior pituitary gland, is known to cause contraction of the mammary myoepithelial cells, which surround milk-producing alveoli, resulting in expulsion of milk towards the nipple, known as the milk-ejection reflex. In engorgement, the milk-ejection reflex may be inhibited due to vascular congestion in the breast preventing oxytocin from reaching the myoepithelial cells;

  2. acupuncture: the stimulation of certain acupuncture points along the skin of the body with acupuncture needles is believed, according to traditional Chinese medicine (TCM), to relieve obstructions in the flow of energy, enabling the body to heal, leading to improved microcirculation and flow of milk;

  3. scraping therapy (Gua-Sha): the stimulation of acupoints, using a scraping motion on the skin, is believed, according to TCM, to improve circulation and metabolism by removing obstructions and revitalising meridians. In TCM, 14 channels of energy, known as meridians, are believed to run throughout the body. Meridians passing just under the skin surface present acupoints;

  4. thermal (continuous) ultrasound therapy: it is thought treatment may facilitate the removal of milk from the engorged breast by facilitating milk let-down, leading to less pain and hardness;

  5. enzyme therapy: believed to be able to suppress inflammation, abate and alleviate pain and oedema and accelerate the circulation of blood and lymph;

  6. anti-inflammatory medication: known to reduce symptoms of inflammation, such as pain, redness and swelling, therefore assumed to relieve the symptoms of engorgement;

  7. cabbage leaves: thought to possibly contain a chemical that the mother's skin absorbs, thus reducing oedema and increasing milk flow. Usually applied chilled which induces vasoconstriction and further decreases oedema;

  8. cold packs: the application of cold is thought to be soothing and to decrease the blood flow to the skin by vasoconstriction, which in turn is believed to decrease engorgement;

  9. massage: gentle breast massage is thought to induce the milk-ejection reflex, mobilise the milk and hence reduce the symptoms of breast engorgement.

Why it is important to do this review

Breastfeeding is the normal way to feed infants, resulting in optimal growth and development. In addition, it provides a stimulus for the bonding process between a mother and her baby, as well as protecting them both from disease. A mother's choice to breastfeed is often hampered by breastfeeding difficulties. Breast engorgement is a common condition affecting up to half of all women who choose to breastfeed (Hill 1994). Apart from causing distressing symptoms for the mother, it can lead to serious complications for the breastfeeding dyad, including the premature cessation of breastfeeding. Earlier systematic reviews on this topic have found insufficient evidence on effective treatments for breast engorgement but in the interim, several new studies have been reported which may assist in finding an effective treatment for this troubling condition. Additionally, in the era of HIV, exclusive breastfeeding has received attention in an effort to prevent mother-to-child transmission. Failure to identify the best forms of treatment of breast engorgement may result in women mixing breast and formula feeding, thus increasing their risk of HIV transmission.

This Cochrane systematic review is an update of the one first published by Snowden 2001, and subsequently re-published in 2010. The previous reviews called for robust research to address the lack of evidence for the treatment of breast engorgement. This review seeks to evaluate current evidence on the best forms of treatment available.

Objectives

To identify the best form of treatment for breast engorgement in breastfeeding women.

Methods

Criteria for considering studies for this review

Types of studies

Randomised and quasi-randomised (method of allocating participants to a treatment that is not strictly random, e.g. by date of birth, hospital record number, alternation) controlled trials evaluating treatments for breast engorgement in breastfeeding women. Cluster-randomised trials were eligible for inclusion. Cross-over trials were not eligible for inclusion.

Studies reported in abstract form were eligible for inclusion, provided that there was sufficient information to allow assessment of eligibility and risk of bias; if information provided in abstracts was insufficient, we tried to contact study authors for more information, or failing that, studies were classified as 'awaiting assessment' until publication of the full trial report. In this version of the review we identified one study reported in abstract form only. It did not contain sufficient information so study authors were contacted and the full report was obtained.

Types of participants

All women receiving any treatment for breast engorgement during breastfeeding.

Types of interventions

  1. Non-medical forms of treatment (acupuncture, cabbage leaves)

  2. Medical treatments (oxytocin, protease)

  3. Medical and non-medical forms of treatment combined

  4. Information and advice on breastfeeding

Types of outcome measures

Primary outcomes
  1. Breast pain (as described by trial authors) (not pre-specified)

  2. Breast induration/hardness (as described by trial authors) (not pre-specified)

  3. Breast swelling (as described by trial authors) (not pre-specified)

  4. Breast engorgement (as described by trial authors) (not pre-specified)

Secondary outcomes
  1. Pyrexia

  2. Mastitis

  3. Breast abscess

  4. Maternal opinion of treatment

  5. Maternal acceptance of treatment

  6. Analgesic requirement

  7. Hospital admission

  8. Woman's confidence in continuing to breastfeed

  9. Cessation of breastfeeding

Search methods for identification of studies

The following methods section of this review is based on a standard template used by the Cochrane Pregnancy and Childbirth Group.

Electronic searches

We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register by contacting their Information Specialist (30 June 2015)

The Register is a database containing over 21,000 reports of controlled trials in the field of pregnancy and childbirth. For full search methods used to populate the Pregnancy and Childbirth Group’s Trials Register including the detailed search strategies for CENTRAL, MEDLINE, Embase and CINAHL; the list of handsearched journals and conference proceedings, and the list of journals reviewed via the current awareness service, please follow this link to the editorial information about the Cochrane Pregnancy and Childbirth Group in The Cochrane Library and select the ‘Specialized Register ’ section from the options on the left side of the screen.

Briefly, the Cochrane Pregnancy and Childbirth Group’s Trials Register is maintained by their Information Specialist and contains trials identified from:

  1. monthly searches of the Cochrane Central Register of Controlled Trials (CENTRAL);

  2. weekly searches of MEDLINE (Ovid);

  3. weekly searches of Embase (Ovid);

  4. monthly searches of CINAHL (EBSCO);

  5. handsearches of 30 journals and the proceedings of major conferences;

  6. weekly current awareness alerts for a further 44 journals plus monthly BioMed Central email alerts.

Search results are screened by two people and the full text of all relevant trial reports identified through the searching activities described above is reviewed. Based on the intervention described, each trial report is assigned a number that corresponds to a specific Pregnancy and Childbirth Group review topic (or topics), and is then added to the Register. The Information Specialist searches the Register for each review using this topic number rather than keywords. This results in a more specific search set which has been fully accounted for in the relevant review sections (Included studies; Excluded studies).

Searching other resources

We searched the reference lists of retrieved studies.

We did not apply any language or date restrictions.

Data collection and analysis

For methods used in the previous version of this review, see Mangesi 2010.

For this update, the following methods were used for assessing the reports that were identified as a result of the updated search.

The following methods section of this review is based on a standard template used by the Cochrane Pregnancy and Childbirth Group.

Selection of studies

Two review authors, one of whom is a content expert (IZG), independently assessed all the studies identified as a result of the search strategy to decide whether they met the inclusion criteria. We resolved any disagreements through discussion. We contacted trial authors for additional information where necessary.

Data extraction and management

We used the standard Cochrane Pregnancy and Childbirth Group data extraction template to extract data from the eligible studies. Both review authors independently extracted the data using the agreed form. We resolved discrepancies through discussion. We entered data into Review Manager software (RevMan 2014) and cross-checked them for accuracy.

Where information regarding any of the identified studies was unclear or incomplete, we attempted to contact authors of the original reports to provide further details. We managed to establish contact with authors of three reports (Ahmadi 2011; Chiu 2010; Roberts 1998) resulting in all three studies being included in the final analysis. Through the assistance of the Campbell and Cochrane Equity and Methods Group, we managed to translate a report written in Farsi (Ahmadi 2011) and extract necessary data.

Assessment of risk of bias in included studies

Two review authors independently assessed risk of bias for each study using the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). We resolved any disagreement by discussion. The following domains were assessed.

(1) Random sequence generation (checking for possible selection bias)

We described for each included study the method used to generate the allocation sequence in sufficient detail to allow an assessment of whether it should produce comparable groups.

We assessed the method as:

  • low risk of bias (any truly random process, e.g. random number table; computer random number generator);

  • high risk of bias (any non-random process, e.g. odd or even date of birth; hospital or clinic record number);

  • unclear risk of bias.

(2) Allocation concealment (checking for possible selection bias)

We described for each included study the method used to conceal allocation to interventions prior to assignment and assessed whether intervention allocation could have been foreseen in advance of, or during recruitment, or changed after assignment.

We assessed the methods as:

  • low risk of bias (e.g. telephone or central randomisation; consecutively numbered sealed opaque envelopes);

  • high risk of bias (open random allocation; unsealed or non-opaque envelopes, alternation; date of birth);

  • unclear risk of bias.   

(3.1) Blinding of participants and personnel (checking for possible performance bias)

We described for each included study the methods used, if any, to blind study participants and personnel from knowledge of which intervention a participant received. We considered that studies were at low risk of bias if they were blinded, or if we judged that the lack of blinding would be unlikely to affect results. We assessed blinding separately for different outcomes or classes of outcomes.

We assessed the methods as:

  • low, high or unclear risk of bias for participants;

  • low, high or unclear risk of bias for personnel.

(3.2) Blinding of outcome assessment (checking for possible detection bias)

We described for each included study the methods used, if any, to blind outcome assessors from knowledge of which intervention a participant received. We assessed blinding separately for different outcomes or classes of outcomes.

We assessed methods used to blind outcome assessment as:

  • low, high or unclear risk of bias.

(4) Incomplete outcome data (checking for possible attrition bias due to the amount, nature and handling of incomplete outcome data)

We described for each included study, and for each outcome or class of outcomes, the completeness of data including attrition and exclusions from the analysis. We stated whether attrition and exclusions were reported and the numbers included in the analysis at each stage (compared with the total randomised participants), reasons for attrition or exclusion where reported, and whether missing data were balanced across groups or were related to outcomes. Where sufficient information was reported, or could be supplied by the trial authors, we re-included missing data in the analyses which we undertook.

We assessed the methods as:

  • low risk of bias (less than 10% missing outcome data; missing outcome data balanced across groups);

  • high risk of bias (e.g. numbers or reasons for missing data imbalanced across groups; `as treated` analysis done with substantial departure of intervention received from that assigned at randomisation);

  • unclear risk of bias.

(5) Selective reporting (checking for reporting bias)

We described for each included study how we investigated the possibility of selective outcome reporting bias and what we found.

We assessed the methods as:

  • low risk of bias (where it is clear that all of the study's pre-specified outcomes and all expected outcomes of interest to the review have been reported);

  • high risk of bias (where not all the study's pre-specified outcomes have been reported; one or more reported primary outcomes were not pre-specified; outcomes of interest were reported incompletely and so could not be used; study failed to include results of a key outcome that would have been expected to have been reported);

  • unclear risk of bias.

(6) Other bias (checking for bias due to problems not covered by (1) to (5) above)

We described for each included study any important concerns we had about other possible sources of bias.

We assessed whether each study was free of other problems that could put it at risk of bias:

  • low risk of other bias;

  • high risk of other bias;

  • unclear whether there is risk of other bias.

(7) Overall risk of bias

We made explicit judgements about whether studies were at high risk of bias, according to the criteria given in the Handbook (Higgins 2011). With reference to (1) to (6) above, we assessed the likely magnitude and direction of the bias and whether we considered it likely to impact on the findings. We planned to explore the impact of the level of bias through undertaking sensitivity analyses, but were unable to do this due to too few studies included in any single analysis.  

Assessment of the quality of the evidence using GRADE

For this update the quality of the evidence was assessed using the GRADE approach as outlined in the GRADE handbook. We looked at cabbage cream versus placebo since one included study addresses two of our primary outcomes.

We planned to report on the following outcomes in the 'Summary of findings' table:

  1. Breast pain

  2. Breast induration/hardness

  3. Breast swelling

  4. Breast engorgement

  5. Analgesic requirement

However, there was no data available on breast induration/hardness, breast swelling or analgesic requirement.

We used GRADEpro Guideline Development Tool to import data from Review Manager 5.3 (RevMan 2014) in order to create a ’Summary of findings’ table. A summary of the intervention effect and a measure of quality for each of the above outcomes was produced using the GRADE approach. The GRADE approach uses five considerations (study limitations, consistency of effect, imprecision, indirectness and publication bias) to assess the quality of the body of evidence for each outcome. The evidence can be downgraded from 'high quality' by one level for serious (or by two levels for very serious) limitations, depending on assessments for risk of bias, indirectness of evidence, serious inconsistency, imprecision of effect estimates or potential publication bias.

Measures of treatment effect

Dichotomous data

For dichotomous data, we presented results as summary risk ratio with 95% confidence intervals. 

Continuous data

For continuous data, we used the mean difference if outcomes were measured in the same way between trials. In future updates, if necessary, we will use the standardised mean difference to combine trials that measure the same outcome, but use different methods.

Unit of analysis issues

Cluster-randomised trials

We had planned to include cluster-randomised trials but we identified none. In future updates of this review, if we identify any eligible cluster-randomised trials we will include them in the analyses along with individually-randomised trials. We will adjust their sample sizes using the methods described in the Handbook [Section 16.3.4 or 16.3.6] using an estimate of the intracluster correlation co-efficient (ICC) derived from the trial (if possible), from a similar trial or from a study of a similar population. If we use ICCs from other sources, we will report this and conduct sensitivity analyses to investigate the effect of variation in the ICC. If we identify both cluster-randomised trials and individually-randomised trials, we plan to synthesise the relevant information. We will consider it reasonable to combine the results from both if there is little heterogeneity between the study designs and the interaction between the effect of intervention and the choice of randomisation unit is considered to be unlikely.

We will also acknowledge heterogeneity in the randomisation unit and perform a sensitivity analysis to investigate the effects of the randomisation unit.

Cross-over trials

Cross-over trials are not eligible for inclusion.

Other unit of analysis issues

Several of the studies included in the review used breasts rather than women as the unit of analysis (McLachlan 1991; Roberts 1995; Roberts 1995a). We are aware that a woman's breasts (engorged or not) are unlikely to be independent of each other and such non-independent data require special methods of analysis (Kvist 2007). In this version of the review, data were not presented in a way that allowed us to include them in the data tables and so we have presented a brief narrative description of results. If usable data become available in the future we will seek statistical help with analysis.

Dealing with missing data

We obtained missing data from a number of study authors (see Characteristics of included studies for details).

For included studies, we noted levels of attrition.

For all outcomes, we carried out analyses, as far as possible, on an intention-to-treat basis, i.e. we attempted to include all participants randomised to each group in the analyses, and all participants were analysed in the group to which they were allocated, regardless of whether or not they received the allocated intervention. The denominator for each outcome in each trial was the number randomised minus any participants whose outcomes were known to be missing.

Assessment of heterogeneity

In this version of the review, as so few trials contributed data and each examined different interventions, we were unable to combine results in meta-analyses. In future updates of the review if more data are added, we plan to assess heterogeneity among trials. We will assess statistical heterogeneity in each meta-analysis using the Tau², I² and Chi² statistics. We will regard heterogeneity as substantial if an I² is greater than 30% and either a Tau² is greater than zero, or there is a low P value (less than 0.10) in the Chi² test for heterogeneity. 

Assessment of reporting biases

In future updates, if there are 10 or more studies in the meta-analysis we will investigate reporting biases (such as publication bias) using funnel plots. We will assess funnel plot asymmetry visually. If asymmetry is suggested by a visual assessment, we will perform exploratory analyses to investigate it.

Data synthesis

We carried out statistical analysis using Review Manager (RevMan 2014). In this version of the review, we could not combine results from trials due to different interventions being evaluated. In future updates, if more data are available, we plan to use fixed-effect meta-analysis for combining data in the absence of moderate or high levels of heterogeneity.

In future updates, if there is clinical heterogeneity sufficient to expect that the underlying treatment effects differ between trials, or if substantial statistical heterogeneity is detected, we will use random-effects meta-analysis to produce an overall summary, if an average treatment effect across trials is considered clinically meaningful. The random-effects summary will be treated as the average of the range of possible treatment effects and we will discuss the clinical implications of treatment effects differing between trials. If the average treatment effect is not clinically meaningful, we will not combine trials. If we use random-effects analyses, the results will be presented as the average treatment effect with 95% confidence intervals, and the estimates of Tau² and I².

Subgroup analysis and investigation of heterogeneity

We were unable to combine any of the studies to allow us to do subgroup analysis because studies were few and they evaluated different interventions.

In future updates of this review, if data do become available, we will carry out subgroup analysis for primary outcomes and only those secondary outcomes which may be confounded by the condition of the woman such as whether the woman had caesarean section or delivered spontaneously. These secondary outcomes include pyrexia, analgesic requirement and hospital admission.

  1. Women who delivered spontaneously and those who delivered by caesarean section

  2. Primiparous and multiparous women

We will assess subgroup differences by interaction tests available within RevMan (RevMan 2014). We will report the results of subgroup analyses quoting the Chi² statistic and P value, and the interaction test I² value.

Sensitivity analysis

In this version of the review we included too few studies (examining several different types of interventions) to allow meaningful sensitivity analysis. We will carry out sensitivity analysis in future updates if more studies are available.

Results

Description of studies

See: Characteristics of included studies and Characteristics of excluded studies.

Results of the search

See: Figure 1

Using the search strategy, we identified 26 reports of 22 studies, examining treatments for breast engorgement in breastfeeding women. After assessing eligibility we included 13 studies (16 reports), one of which was in the form of an abstract (Ahmadi 2011). Additional information was sought from the authors who sent the full text, in Farsi. This was translated with the help of the Campbell and Cochrane Equity Methods Group.

Included studies

We have included 13 studies carried out over a period of more than 60 years (from Ingelman-Sundberg 1953 to Batista 2014), during which attitudes towards breastfeeding and the types and availability of treatments for women with breast engorgement have changed considerably.

All of the included studies focused on women with signs and symptoms of breast engorgement. In most of the studies, women with swollen, hard, painful breasts (and sometimes with pyrexia) were generally recruited in the early postnatal period (two to 10 days postpartum). In the study by Kvist 2007 women were recruited at breastfeeding clinics rather than in hospital postnatal wards, and may have been breastfeeding for some time, although the majority were seen within two weeks of giving birth. In one study, the focus was specifically on women who had caesarean births (Robson 1990), and in another on women who sought care at a human milk bank.(Batista 2014).

The studies we have included in the review examined the effects of a broad range of interventions, and data were sometimes presented in a way that did not allow us to enter them into RevMan tables (Batista 2014; Kvist 2004; Murata 1965; Roberts 1995; Roberts 1995a; Robson 1990); for these studies we have presented a brief narrative summary of findings. Interventions included:

  1. acupuncture versus usual care (Kvist 2004; Kvist 2007);

  2. acupressure versus hot and cold compresses (Ahmadi 2011);

  3. cabbage leaves (cold versus room temperature leaves (Roberts 1995)); chilled cabbage leaves versus chilled gel packs (Roberts 1995a); cabbage leaf extract versus placebo (Roberts 1998);

  4. cold packs versus routine care (Robson 1990);

  5. protease complex tablets versus placebo (Murata 1965);

  6. ultrasound versus sham ultrasound (McLachlan 1991);

  7. serrapeptase versus placebo (Kee 1989);

  8. Gua-Sha (scraping) therapy versus hot packs and massage (Chiu 2010);

  9. subcutaneous oxytocin versus placebo (Ingelman-Sundberg 1953);

  10. electromechanical breast massage followed by mechanical pumping versus manual breast massage followed by manual pumping (Batista 2014).

The broad range of interventions studied meant that we were not able to pool data from more than one study in any of the analyses.

Further details on the women participating in the included studies and descriptions of the interventions can be found in the Characteristics of included studies tables.

Excluded studies

We excluded nine studies (10 reports) identified by the search strategy. The main reasons for exclusion were that studies examined the prevention of breast engorgement (Nikodem 1993) in women whose breasts were not yet engorged, or examined interventions to suppress lactation in women who did not intend to breastfeed, rather than examining interventions to treat the symptoms of engorgement in women who were breastfeeding their babies (Booker 1970; Filteau 1999; Garry 1956; King 1958; Phillips 1975; Roser 1966; Ryan 1962). Finally, we excluded one study that was otherwise eligible for inclusion, because not all of the women recruited were receiving an intervention to treat breast engorgement (Stenchever 1962).

Approximately half of the women recruited in the Nikodem 1993 study did not have symptoms of breast engorgement and the intervention aimed to prevent rather than treat symptoms in these women. Separate results were not available for women with engorged breasts seeking symptom relief. We have provided further information on these studies in the Characteristics of excluded studies tables.

Risk of bias in included studies

We found it difficult to assess risk of bias in the included studies as the methods used in the trials were not generally well-described. Most authors reported that the trial was a randomised controlled trial but did not describe how sequence generation or allocation concealment was performed. Unavailability of this information resulted in the risk of bias being categorised as unclear.

Please see Figure 1 and Figure 2 for a summary of 'Risk of bias' assessments.

Figure 1.

'Risk of bias' graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.

Figure 2.

'Risk of bias' summary: review authors' judgements about each risk of bias item for each included study.

Allocation

In two studies we judged that the methods used to conceal group allocation at the point of randomisation were adequate; in these studies group assignments were concealed in sealed opaque sequentially numbered envelopes (Kvist 2004; Kvist 2007). In all of the remaining studies, we assessed that methods to conceal allocation were inadequate or unclear. Quasi-randomisation was used in four trials; group allocation was by odd or even case-note number in the Ingelman-Sundberg 1953 trial, by day of the week in the Murata 1965 trial, and in the two studies by Roberts (Roberts 1995; Roberts 1995a), all women received both the experimental and control interventions, as breasts rather than women were randomised. In one study a "balanced block randomisation sequence" was used, but it was not clear what methods were used to conceal group allocation (McLachlan 1991). Similarly, a "computer-generated block randomisation list" was produced by Chiu 2010, but the method of allocation concealment was not described. One of the study authors was contacted for clarification but information on sequence generation only was provided. Two studies (Ahmadi 2011; Kee 1989) were characterised as randomised controlled trials but neither sequence generation nor allocation concealment were reported; the Ahmadi paper only states that the women were randomly assigned to one intervention or the other in a way that would create two intervention groups of equal size. Even distribution of baseline characteristics (education level, career, number of births and type of birth) suggests that randomisation was adequate, but incomplete reporting resulted in the study being categorised as unclear. Attempts were made to contact the Kee study authors to clarify selection bias but neither the journal in which the paper was published, nor the affiliated institution knew of the authors whereabouts. Allocation concealment was classified as unclear in the Roberts 1998 study because even though group assignments were placed in sealed envelopes, it is not stated whether they were opaque or non-opaque. Although coin toss was used for initial random sequence generation in the Batista 2014 study, intervention options were alternated thereafter, placing this study at high risk of selection bias. Finally, in the study by Robson 1990 there were serious problems with the way randomisation was carried out; a table of random numbers was used to decide the randomisation sequence but the allocation sequence was not necessarily observed, so, for example, women with the most distressing symptoms assigned to the control group were moved into the intervention group, and there was no intention-to-treat analysis.

Blinding

In studies where different types of interventions were compared, blinding participants and clinical staff would not be feasible and was not attempted (Ahmadi 2011; Batista 2014; Chiu 2010; Kvist 2004; Kvist 2007; Roberts 1995; Roberts 1995a; Robson 1990). The lack of blinding (of women, staff and outcome assessors) in these studies may represent a serious source of bias, as many of the outcomes measured (subjective views about treatment and assessment of symptoms) may have been influenced by knowledge of treatment assignment. In the study by McLachlan 1991 comparing ultrasound versus sham ultrasound, it was reported that women and staff were blind to which machine was which. However, in this study breasts rather than women were randomised and one breast may have been randomised to receive ultrasound and the other sham treatment. It was reported that the same machine was always used to treat the same breast. It is not clear how convincing to women and staff this attempt at blinding was, and it is difficult to imagine full compliance with this blinding procedure in the context of busy postnatal wards. Four other studies used placebo methods: in Murata 1965, protease complex tablets were compared with lactose-containing placebo tablets; in the Ingelman-Sundberg 1953, subcutaneous oxytocin was compared with physiological saline injections; in Kee 1989, oral serrapeptase was compared with specially made control tablets that were identical in appearance and given according to the same regimen; and in the Roberts 1998 trial a cream containing cabbage leaf extract was compared with a base/placebo cream, with rosewater added to both creams to camouflage the residual odour of cabbage. It is unclear from the Murata 1965 report whether the tablets used were identical, hence we have categorised this study as unclear, as opposed to the other studies which were judged to be at low risk of performance bias.

In terms of outcome assessment, there was no mention of blinding of outcome assessors in three studies (Batista 2014; Ingelman-Sundberg 1953; Kvist 2007). Outcome assessment was clearly not blinded in five studies (Ahmadi 2011; Kvist 2004; Roberts 1995; Roberts 1995a; Robson 1990) and in the remaining five studies, there was evidence that outcome assessment had been carried out by assessors blinded to group assignment (Chiu 2010; Kee 1989; McLachlan 1991; Murata 1965; Roberts 1998).

Incomplete outcome data

We assessed that the level of attrition bias was unclear in one older study (Ingelman-Sundberg 1953), which did not mention how incomplete outcome data were addressed, and in the study by Batista 2014, where the final sample size is more than 10-fold smaller than the calculated sample size. Three studies were assessed as high risk of attrition bias (Kvist 2004; McLachlan 1991; Robson 1990) as information on loss to follow-up, or denominators in the results section, may not have been explicit. No attrition was apparent in the studies by Roberts (Roberts 1995; Roberts 1995a; Roberts 1998), and there appeared to be low levels of attrition (less than 5%) in the studies by Ahmadi 2011, Chiu 2010, Kee 1989, Kvist 2007, and Murata 1965.

Selective reporting

We did not have study protocols to adequately assess within-study selective reporting bias. We assessed selective reporting bias by comparing what was listed in the methods section of the study with what was reported in the results section. Most studies (Ahmadi 2011; Chiu 2010; Kee 1989; Kvist 2007; McLachlan 1991; Murata 1965; Roberts 1995a; Roberts 1995; Robson 1990) reported outcomes that were pre-stated in the methods section and on outcomes of interest in this review. There is an unclear risk of bias in two studies: Roberts 1998 because whilst the authors have mentioned the outcomes they intended to assess, they presented the results with the two groups combined; in Ingelman-Sundberg 1953, the authors report their outcomes in percentages, not in numbers out of the totals, which made it difficult to determine the denominators. Kvist 2004 carries a risk of bias as the authors mention that the study had to be stopped prematurely but no data are given. Also, they do not mention in the results one of the outcomes (resistance of breast tissue), which was listed in the methods' section. Other outcomes are mentioned, as non-significant results, but are not reported adequately. In the study by Batista 2014, participants were evaluated based on clinical exam and thermography but only thermography is reported for both groups placing this study at high risk of reporting bias.

Other potential sources of bias

There was considerable baseline imbalance in the study by Robson 1990. Women in the control group had much lower pre-test pain scores. There was also some deviation from protocol in this study: three women who were described as having "heightened distress levels" assigned to the intervention group were moved into the control group as this was perceived as being less demanding of their time, and one mother with severe discomfort asked to be assigned to the intervention group. In all, the randomisation schedule was not observed in eight cases. This represents a serious source of bias. There was no intention-to-treat analysis.

In another study (Roberts 1998), a significant baseline imbalance was found in the number of primiparas. Authors were contacted but no explanation was found. This may have been due to chance or a small sample size but may also have been due to possible problems with allocation concealment or compromised blinding, hence we made a judgement of possible high risk of bias.

There was considerable risk of bias in Batista 2014; no baseline characteristics were provided for included participants, although varying degrees of engorgement were alluded to, implying the possibility of baseline imbalance. Additionally, the study was severely underpowered, limiting its precision. No statement of conflict of interest or sponsorship was provided, raising the possibility of industry funding.

In three of the included studies, randomisation and analysis was at the level of breasts rather than women (McLachlan 1991; Roberts 1995; Roberts 1995a). McLachlan 1991 state that in their study, when the visual analogue scale was used, it was not always easy for women to make a clear distinction between the left and right breast. This may be an indication that having an individual breast as a unit of analysis is not ideal. In the studies there was no adjustment made for the non-independence of breasts, and we found interpretation of results difficult. This difficulty was exacerbated in the study by Roberts 1995, because the pretest rating of symptoms was for both breasts together (an overall rating), whereas at post-test, women provided ratings for separate breasts. It was therefore not possible for us to understand the possible differences between pre- and post-test scores.

In one study (Kvist 2004), insufficient information was available, due to lack of clarity in reporting, to assess whether an important risk of bias exists. In the Murata 1965 and Kee 1989 studies the active tablets used in the trial were supplied by a pharmaceutical company, hence it was unclear whether a vested interest may have influenced study results. The remaining studies (Ahmadi 2011; Chiu 2010; Ingelman-Sundberg 1953; Kvist 2007) appeared to be free of other sources of bias.

We were not able to examine possible publication bias using funnel plots because of the small number of studies included in the review.

Effects of interventions

See: Summary of findings for the main comparison Cabbage cream for breast engorgement during lactation

Interventions to treat breast engorgement: 13 studies with 919 women

We included 13 studies with 919 breastfeeding women; 171 of whom were analysed at the individual breast level (Ahmadi 2011; McLachlan 1991; Roberts 1995; Roberts 1995a). We were unable to pool any results from studies in meta-analysis because of the broad range of interventions examined, and the way in which outcomes were assessed and reported in these trials. We have set out separate comparisons for each type of intervention in the text below, and in the data tables; in some studies we were not able to include all outcome data in tables because of the form in which results were presented in research reports; for these outcomes we provide a brief description of findings as reported by the trial authors. Most of the studies did not provide usable information on the review's primary outcomes (pain, breast engorgement, breast swelling and breast induration), and so we have set out findings for both primary and secondary outcomes together.

Acupuncture to treat breast engorgement: two studies with 293 women
Primary and secondary outcomes

Two studies examined the effects of acupuncture on breast engorgement (Kvist 2004; Kvist 2007). In both studies there were three treatment groups: advice and usual care (which might include the use of oxytocin nasal spray at the discretion of the midwife); advice and acupuncture, excluding the SP6 acupoint; and advice and acupuncture, including the SP6 point. Advice consisted of information on breastfeeding frequency, duration and technique, breast emptying, and the application of unrefined cotton wool as needed. Results for resolution of symptoms were very similar for women in the two acupuncture groups in the Kvist 2007 study, so we have combined them in the data tables.

We were unable to include data from the Kvist 2004 study in analyses because results were not set out separately for the three randomised groups in the published report and were not available from the authors. The authors however report that there were no significant differences on day three of treatment between the three groups in the severity index (a sum score for breast tension, erythema and pain) or for maternal satisfaction with breastfeeding. The percentage of mothers in Group 1 who were prescribed oxytocin nasal spray by the midwives was 86%. The study by Kvist 2004 was discontinued prematurely because the authors felt it necessary to include cultivation of breast milk from all participants and follow-up of the mothers after six weeks. In Kvist 2007, the two intervention groups were combined during data analysis as suggested in section 16.5 of the Cochrane Handbook (Higgins 2011). There was no difference in cessation of breastfeeding where six women stopped breastfeeding in the group where oxytocin nasal spray was used (the midwives gave oxytocin nasal spray to 100% of the mothers in Group 1) compared to three women in the group where acupuncture (excluding SP-6 acupoint) was used (risk ratio (RR) 0.50, 95% confidence interval (CI) 0.13 to 1.92; one study; 140 women - data not shown).

Both studies provided information on the review's primary outcomes in the form of a severity index (SI), which included breast tension and pain. Significantly more mothers in the acupuncture group had less severe breast symptoms on days three and four of treatment in comparison with the non-acupuncture group. The mothers' expression of satisfaction with the breastfeeding experience did not differ significantly between the groups.The number of women prescribed antibiotics may represent a proxy measure of mastitis; results from Kvist 2007 show that there was no difference between acupuncture and control groups in prescription antibiotics (RR 0.61, 95% CI 0.32 to 1.16; data not shown).

The number of women with breast abscess was reported in Kvist 2007; women in the acupuncture group were less likely to develop an abscess compared to women receiving routine care (RR 0.20, 95% CI 0.04 to 1.01; one study; 210 women), Analysis 1.1.

Findings in the Kvist 2007 study favoured the acupuncture group, with more women in the acupuncture group, having less severe symptoms on days four and five of contact, compared to women in the control group (RR 0.84, 95% CI 0.70 to 0.99; one study; 210 women), Analysis 1.2.

A lower rate of pyrexia was observed in women who received acupuncture for breast engorgement compared to women receiving standard care (RR 0.82, 95% CI 0.72 to 0.94; one study; 210 women), Analysis 1.3.

Acupressure versus hot and cold compresses: one study with 70 women
Primary and secondary outcomes

This study, comparing the effect of acupressure (intervention group) and intermittent hot and cold compresses (control group) (Ahmadi 2011), could not be analysed in RevMan 2014 because of the way data were presented (using individual breasts as the unit of analysis). Both treatments were found to be effective in decreasing breast engorgement in lactating mothers (P < 0.001), with hot and cold compresses being more effective than acupressure (P < 0.001).

Cabbage leaves to treat breast engorgement: three studies with 101 women
Primary and secondary outcomes

Three studies by the same first author examined cabbage leaves to reduce symptoms of breast engorgement, and collected information on pre- and post-treatment pain scores in randomised trials. Two studies assessed the use of cabbage leaves: chilled versus room temperature cabbage leaves (Roberts 1995), and chilled cabbage leaves versus chilled gel packs (Roberts 1995a), whilst the third study evaluated the use of cabbage leaf extract, in the form of a cream, versus placebo (Roberts 1998). In two studies (Roberts 1995; Roberts 1995a), breasts rather than women were randomised, and results were not reported in a way that allowed us to enter data into RevMan 2014. In the study comparing chilled cabbage leaves and chilled gel packs (Roberts 1995a), it was reported that women in both groups had significant reductions in pain scores following treatment (30% for the cabbage leaves and 39% for the gel packs), but that there were no differences between groups (data not shown). While both treatments appeared to produce some alleviation of discomfort, it is likely that the subjective ratings on the pain ruler were susceptible to a placebo effect. Two-thirds of women stated that they preferred the cabbage leaves because they gave a more immediate effect, while others felt that the chilled gel packs gave a more lasting effect. In the second study comparing chilled versus room temperature cabbage leaves, again authors reported that both groups had significantly less pain following treatment (37% reduction in pain with room temperature cabbage leaves and a 38% reduction with chilled cabbage leaves), but that there was no difference at all between the randomised groups (Roberts 1995) (data not shown). The lack of difference in the pain ratings suggests that chilling does not influence the purported effectiveness of cabbage leaves. Study authors felt that the drop in pain ratings could have been at least partially caused by a placebo effect. The attention of clinicians could have reduced anxiety in the new mothers and consequently reduced pain levels. Study authors concluded that it is not necessary to chill cabbage leaves before using them, since chilling has no effect on the efficacy of the treatment.

In Roberts 1998 there was no significant difference between the cabbage leaf extract group and the placebo group with regards to breast engorgement (mean difference (MD) 0.20, 95% CI -0.18 to 0.58; one study; 39 women; low-quality evidence), Analysis 2.1. Both groups perceived the creams as having some efficacy but the lack of significant difference between the mean pain scores of the experimental and control groups (MD 0.40, 95% CI -0.67 to 1.47; one study; 39 women; low-quality evidence), Analysis 2.2, on any of the indicators, suggests that any action of the cabbage leaf extract tested is likely to be a placebo effect. The perception of the control group mothers that the discomfort and hardness were decreasing supports this inference. Furthermore, the magnitude of this perceived relief was low and in the range of a placebo effect. Of note is that breastfeeding was observed to have significantly more effect than cabbage cream on the perception of hardness of breast tissue and discomfort (Roberts 1998).

Gua-Sha (scraping) therapy versus hot packs and massage: one study with 54 women
Primary and secondary outcomes

In the study comparing Gua-Sha (scraping) therapy with hot packs and massage (Chiu 2010), Gua-Sha therapy, applied to acupoints ST16, ST18, SP17 and CV17, was more beneficial than hot packs and massage for the relief of breast engorgement, though both interventions significantly decreased breast temperature, engorgement, pain and discomfort at five and 30 minutes post-treatment. There was marked difference in the intervention group at first five minutes post-intervention: breast engorgement scale 4.01 (standard deviation (SD) 0.91) for the intervention group compared to 6.43 (SD: 1.17) for the hot packs and massage group (MD -2.42, 95% CI -2.98 to -1.86; one study; 54 women), Analysis 3.1. Breast pain was markedly improved at five minutes in the Gua-Sha therapy group: 4.25 (SD: 1.07) compared to 6.26 (SD 1.14) in the control group (MD -2.01, 95% CI -2.60 to -1.42; one study; 54 women), Analysis 3.2. There was also marked improvement in the breast discomfort scales in the first five minutes in the Gua-Sha therapy group (MD -2.33, 95% CI -2.81 to -1.85; one study; 54 women), Analysis 3.3.

Ultrasound (thermal, continuous) treatment for breast engorgement: one study with 109 women
Primary and secondary outcomes

McLachlan 1991 examined ultrasound versus sham ultrasound in a study where breasts rather than women were randomised (women may have had active treatment on both breasts, sham treatment on both breasts, or one breast receiving active, and the other receiving sham ultrasound). No adjustment was made for the non-independence of breasts and most of the results were difficult to interpret. When women who had the same treatment (either active or sham ultrasound) to both breasts were compared, the numbers requiring analgesia were very similar (RR 0.98, 95% CI 0.63 to 1.51; one study; 45 women; low-quality evidence), Analysis 4.1. Trial authors report that both sham and active treatment were associated with significant reductions in subjective ratings of pain and hardness, based on visual analogue scales comparing the paired pre-treatment and post-treatment ratings for each breast, but there were no differences between groups at the end of treatment. The effect of treatment on hardness, as measured by tonometry, was small and inconsistent providing further evidence of a placebo effect. It was also reported that there were no differences in the duration of breastfeeding (18 weeks) for women in the different treatment groups, but actual rates in each group were not reported. The therapeutic effect observed in both groups was attributed to the warmth, rest, massage, attention and emotional, practical and informational support provided by the physiotherapists in the course of treatment. In addition, the study authors thought that the perceived benefit of being the recipient of modern technology may have contributed to the observed placebo effect.

Cold packs for breast engorgement: one study with 88 women
Primary and secondary outcomes

In a non-blinded study women who had caesarean deliveries and who developed symptoms of breast engorgement were randomised to treatment and control groups (breast-shaped cold packs worn in a halter versus routine care) (Robson 1990). Women in the intervention group seemed to experience a reduction in pain intensity post-test. The author reported a decrease in mean pain intensity score from 1.84 (SD 0.65) to 1.23 (SD 0.68) compared with an increase in the control group from 1.50 (SD 0.71) to 1.79 (SD 0.72) (data not shown). However, the differences between groups at baseline, and the failure to observe randomisation (women with "heightened distress" were moved into the control group), make results difficult to interpret. It was not possible to include these results in the data and analyses.

Electromechancial massages and pumping: one study with 16 women

One study (Batista 2014) found a decrease in breast temperature (P = 0.0349) following electromechanical massage and pumping in comparison to manual methods; however, the alternating method of sequence generation, lack of blinding, and possible selective reporting, place this study at high risk of bias.

Protease complex to treat breast engorgement: one study with 59 women
Primary and secondary outcomes

A quasi-randomised controlled trial by Murata 1965 examined the effects of protease complex (a plant enzyme) versus placebo in 59 women complaining of painful, swollen breasts, three to five days postpartum. Outcomes measured included improvements in pain and swelling, and overall rating of recovery. Additional observations recorded included size of breast and shape of nipple. Blood samples were taken before and after treatment to monitor coagulation factors (bleeding, coagulation and prothrombin time).

Women in the active treatment group were less likely to have no improvement in pain (RR 0.17, 95% CI 0.04 to 0.74; one study; 59 women), Analysis 5.1, and swelling (RR 0.34, 95% CI 0.15 to 0.79; one study; 59 women), Analysis 5.2, when symptoms were clinically assessed on the fourth day after commencement of treatment. Compared with controls, women receiving the active protease complex were also less likely to experience no overall change in their symptoms or worse symptoms (RR 0.26, 95% CI 0.12 to 0.56; one study; 59 women), Analysis 5.3.

It was not clear how many of the women participating in this trial were breastfeeding during the treatment period. No side effects were observed and coagulation factors were unchanged before and after treatment.

Oxytocin for the treatment of breast engorgement: one study with 45 women
Primary and secondary outcomes

A study carried out in the early 1950s examined the effectiveness of subcutaneous oxytocin, which was administered daily until symptoms resolved (Ingelman-Sundberg 1953). Participants received either oxytocin or an injection of normal saline. The main outcome in this study was duration of treatment. Overall, seven of the 45 women included in the study still had symptoms three days after starting treatment; five of the 20 women in the oxytocin group and two of the 25 women in the placebo group. Although more women in the oxytocin group had no resolution of symptoms compared with controls, there was no difference between groups (RR 3.13, 95% CI 0.68 to 14.44; one study; 45 women), Analysis 6.1.

Serrapeptase versus placebo: one study with 70 women
Primary and secondary outcomes

A double-blind randomised controlled trial by Kee 1989 examined the effects of oral serrapeptase, a proteolytic enzyme derived from the silk worm, on 70 women recruited from an urban hospital in Singapore diagnosed with breast engorgement. During the study breastfeeding was encouraged and concomitant breast massage and milk expression was allowed (Kee 1989).

A higher rate of improvement of breast engorgement was observed in the group receiving serrapeptase compared to placebo (RR 0.36, 95% CI 0.14 to 0.88; one study; 70 women), Analysis 7.1, however, there was no difference in the rate of improvement in breast swelling between groups (RR 0.75, 95% CI 0.36 to 1.55; one study; 70 women), Analysis 7.2.

Nor was any difference found in the rate of improvement of breast pain between the group of women receiving serrapeptase and the control group (RR 0.56, 95% CI 0.21 to 1.49; one study; 70 women), Analysis 7.3.

Discussion

Summary of main results

In this review we have included data from 13 randomised and quasi-randomised controlled trials, involving 919 breastfeeding women, looking at 10 different types of interventions for treating breast engorgement.

For several interventions with sham or placebo comparisons (ultrasound, cabbage leaf extract cream, and subcutaneous oxytocin), there was no evidence that interventions were associated with a more rapid or effective resolution of symptoms; in these studies women tended to have improvements in pain and other symptoms over time whether or not they received active treatment. The improvement in symptoms may be partly explained by the placebo effect or, it may be due to the fact that symptoms resolved spontaneously as women continued to breastfeed.

Non-medical interventions

No differences were observed in the one study comparing acupuncture with usual care (advice and oxytocin spray) in terms of cessation of breastfeeding. In another study comparing cabbage leaf extract with placebo, no differences were observed in breast pain or breast engorgement. In one study comparing Gua-Sha therapy with hot packs and massage, improvements were observed in both breast pain and breast engorgement. There was no difference between ultrasound and sham treatment in analgesic requirement.

Results from individual trials that could not be included in data analysis suggested that there were no differences between room temperature and chilled cabbage leaves and between chilled cabbage leaves and gel packs, with all interventions producing some relief. Intermittent hot/cold packs applied for 20 minutes twice a day were found to be significantly more effective than acupressure. Acupuncture did not improve maternal satisfaction with breastfeeding, but in one study women reported less severe symptoms and were less likely to develop a breast abscess. In another study, women who received breast-shaped cold packs were more likely to experience a reduction in pain intensity than women who received usual care; however, the differences between groups at baseline, and the failure to observe randomisation, make this study at high risk of bias. One study found a decrease in breast temperature (P = 0.03) following electromechanical massage and pumping in comparison to manual methods; however, the alternating method of sequence generation, lack of blinding, and possible selective reporting, place this study at high risk of bias.

Medical interventions

Women treated with protease complex were less likely to have no improvement in pain and swelling on the fourth day of treatment and less likely to experience no overall change in their symptoms or worsening of symptoms. It should be noted that it is more than 40 years since the study was carried out, and we are not aware that this preparation is used in current practice. Subcutaneous oxytocin provided no relief at all in symptoms at three days. Serrapeptase was found to produce some relief in breast pain, induration and swelling, when compared to placebo, with a high number of participants given serrapeptase experiencing slight to no improvement in overall breast engorgement, swelling and breast pain, but differences were not significant.

Overall completeness and applicability of evidence

All available randomised and quasi-randomised controlled trials investigating the treatment of breast engorgement in breastfeeding women were included in this review, with no language restrictions. We attempted to be as inclusive as possible by going to great lengths to contact authors of reports requiring clarification of methodology or results.

The studies included in this review were conducted in a variety of countries (Australia, Brazil, Iran, Japan, Singapore, Sweden, Taiwan, USA); however all but two were from high-resource settings, hence limiting the applicability of the findings.

There is also little information on what women think of particular interventions; cold packs, for example, may be soothing for some women or may be uncomfortable for others; trials included in the review did not tend to report what women's views and preferences regarding treatment options were, apart from one study (Roberts 1995) in which two-thirds of women stated that they preferred cabbage leaves to gel packs, with some mothers volunteering the information that cabbage leaves gave a stronger, more immediate effect, while others felt that chilled gel packs gave a more lasting effect in the treatment of breast engorgement.

The studies included in this review looked at a broad range of different interventions, and most of the studies did not report findings on key outcomes such as breast engorgement, breast pain, breast swelling, induration, impact of interventions on infection, breastfeeding practices, and cessation of breastfeeding. Whilst studies did examine improvement in symptoms, and this is certainly an outcome that is likely to be important to women, this outcome is difficult to interpret as symptoms are subjective and are likely to change over time with or without active intervention.

Quality of the evidence

Despite the contributions made by the authors and study participants in the 13 studies included in this review, we found the evidence for most outcomes to be at high risk of bias due to the small sample sizes (imprecision), inadequate sequence generation and allocation concealment (selection bias), lack of blinding of women, staff and outcome assessors (performance bias and detection bias), and potential conflict of interest, with four studies (Kee 1989; McLachlan 1991; Murata 1965; Roberts 1998) receiving funding from industry.

The lack of blinding in studies may mean that evidence regarding symptoms (reported by women or assessed by clinicians) may be at high risk of bias. Even though blinding of women and clinicians cannot always be conducted, where a placebo is not available, blinding of outcome assessors should be ensured to keep detection bias to a minimum. Most of the studies did not have sufficient statistical power to detect differences between groups and so results are not conclusive, and while outcomes that occur relatively infrequently were not generally reported, it is unlikely that these studies would have been large enough to show possible differences. The studies also had relatively short follow-up periods (as outcomes such as symptom improvement are apparent within a few days), which meant that information on longer-term outcomes such as duration of exclusive breastfeeding, or breastfeeding cessation was not available. Randomisation of breasts in some studies may mean that results are at high risk of bias as breasts are not independent; asking mothers who are not blinded to breast assignments to rate individual breasts (when at pre-test they provided a single rating for both breasts) may lead to findings that are at best, difficult to interpret, and at worst, not valid.

Three of the included studies (McLachlan 1991; Roberts 1995; Roberts 1995a) were very difficult to interpret as analysis was by individual breast and not by individual women. As reported by authors, it was not always easy for women to make a clear distinction between the left and right breast, making the evidence questionable. In Robson 1990, the randomisation procedure was not adhered to: women with the most distressing symptoms assigned to the control group were moved into the intervention group.

The overall quality as assessed using the GRADE approach was found to be low for the comparison of cabbage cream versus placebo for breast pain and breast engorgement. This was due to limitations in study design and the small number of women in the single study contributing data to this analysis. Other outcomes such as breast hardness, swelling or analgesic requirement could not be assessed because they were not reported.

Potential biases in the review process

We acknowledge that there is potential for bias in the review process as assessment of risk of bias, for example, is not an exact science and is subject to individual interpretation. We attempted to minimise this by: 1) having two review authors independently assess risk of bias and carry out data extraction; 2) contacting study authors if study methods or results were unclear; and 3) consulting a third party if we were unable to resolve dilemmas.

Agreements and disagreements with other studies or reviews

Clinical practice guidelines in the UK (NICE 2006) broadly agree with this review concluding that cabbage leaves and cold packs may be helpful for symptom relief, but that evidence on the effectiveness of these interventions is not strong.

Authors' conclusions

Implications for practice

There is insufficient evidence from trials to recommend the widespread implementation of a particular treatment for breast engorgement. At the same time, treatments such as hot/cold packs or cabbage leaves applied to the breast may be soothing, are unlikely to be harmful, are inexpensive and readily available.

Implications for research

There has been relatively little research in this area with only three new clinical trials being published in the last five years. Consequently, current treatment recommendations are largely based on anecdotal evidence and theoretical assumptions. The fact that they have remained unchanged over the last 20 years, attests to the urgent need for research in this field. What evidence is available, has methodological limitations resulting in a high risk of bias. Studies where individual breasts have been randomised are particularly difficult to interpret due to the unreliability of the results; hence this study design should be avoided in future research. Overcoming problems associated with lack of blinding and subsequent placebo effect is a particular challenge in this area. Comparing alternative treatment options using a cluster-randomised design rather than randomising individual women may be a possible way forward to ensure bigger numbers and to avoid contamination. In cases where cluster-randomised trials are not feasible, using an objective instrument for measuring breast engorgement, such as tonometry for measuring breast induration/hardness, may be a solution. At the same time, studies should also measure patient-important outcomes, such as breast pain and difficulty breastfeeding. Using the CONSORT statement for the reporting of randomised controlled trials, will also aid in interpretation and comparison of future studies. Finally, more robust research is necessary to confirm or dispute the promising effect of interventions such as serrapeptase, protease complex, hot/cold packs, scraping therapy, acupuncture and cabbage leaves for the treatment of breast engorgement in breastfeeding women. In addition, research evidence in the form of randomised controlled trials is needed to support current treatment recommendations.

Acknowledgements

This project was supported by the National Institute for Health Research, via Cochrane Infrastructure funding to Cochrane Pregnancy and Childbirth. The views and opinions expressed therein are those of the authors and do not necessarily reflect those of the Systematic Reviews Programme, NIHR, NHS or the Department of Health.

Lindeka Mangesi was awarded a fellowship by the South African Cochrane Centre through a grant received from the Effective Health Care Research Consortium www.evidence4health.org, which is funded by UKaid from the UK Government for International Development.

We acknowledge Therese Dowswell for her contribution in the initial review.

We thank the following members of the Campbell and Cochrane Equity Methods Group: Peter Tugwell, Jordi Pardo, Elizabeth Tanjong-Ghogomu and George Wells for their assistance with interpreting data and assessment of risk of bias. In particular we would like to acknowledge Siavash Ghazvinian for translating the Farsi report and assisting with data extraction.

We acknowledge Livia Puljak, from Cochrane Croatia, for her assistance with final editing of the review.

We thank the editorial staff and peer reviewers of the Cochrane Pregnancy and Childbirth Group for their patience, advice, support and guidance in improving the quality of this review.

Data and analyses

Download statistical data

Comparison 1. Acupuncture versus usual care
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Breast abscess1210Risk Ratio (M-H, Fixed, 95% CI)0.2 [0.04, 1.01]
2 Lowest Severity Index score (day 5) (combined measurement of breast erythema, tension and pain)1210Risk Ratio (M-H, Fixed, 95% CI)0.84 [0.70, 0.99]
3 Pyrexia (advised to take antipyrexials)1210Risk Ratio (M-H, Fixed, 95% CI)0.82 [0.72, 0.94]
Analysis 1.1.

Comparison 1 Acupuncture versus usual care, Outcome 1 Breast abscess.

Analysis 1.2.

Comparison 1 Acupuncture versus usual care, Outcome 2 Lowest Severity Index score (day 5) (combined measurement of breast erythema, tension and pain).

Analysis 1.3.

Comparison 1 Acupuncture versus usual care, Outcome 3 Pyrexia (advised to take antipyrexials).

Comparison 2. Cabbage leaf extract versus placebo
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Breast engorgement (Hill and Humenich Breast engorgement scale)139Mean Difference (IV, Fixed, 95% CI)0.20 [-0.18, 0.58]
2 Breast pain (Bourbonaise pain scale)139Mean Difference (IV, Fixed, 95% CI)0.40 [-0.67, 1.47]
Analysis 2.1.

Comparison 2 Cabbage leaf extract versus placebo, Outcome 1 Breast engorgement (Hill and Humenich Breast engorgement scale).

Analysis 2.2.

Comparison 2 Cabbage leaf extract versus placebo, Outcome 2 Breast pain (Bourbonaise pain scale).

Comparison 3. Gua-Sha therapy versus hot packs and massage
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Breast engorgement - 5-minute post-intervention (Subjective Breast Engorgement Scale)154Mean Difference (IV, Random, 95% CI)-2.42 [-2.98, -1.86]
2 Breast pain - 5-minute post-intervention (Subjective Breast Engorgement Scale)154Mean Difference (IV, Fixed, 95% CI)-2.01 [-2.60, -1.42]
3 Breast discomfort - 5-minute post-intervention (Subjective Breast Engorgement Scale)154Mean Difference (IV, Fixed, 95% CI)-2.33 [-2.81, -1.85]
Analysis 3.1.

Comparison 3 Gua-Sha therapy versus hot packs and massage, Outcome 1 Breast engorgement - 5-minute post-intervention (Subjective Breast Engorgement Scale).

Analysis 3.2.

Comparison 3 Gua-Sha therapy versus hot packs and massage, Outcome 2 Breast pain - 5-minute post-intervention (Subjective Breast Engorgement Scale).

Analysis 3.3.

Comparison 3 Gua-Sha therapy versus hot packs and massage, Outcome 3 Breast discomfort - 5-minute post-intervention (Subjective Breast Engorgement Scale).

Comparison 4. Ultrasound versus sham treatment
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Analgesic requirement145Risk Ratio (M-H, Fixed, 95% CI)0.98 [0.63, 1.51]
Analysis 4.1.

Comparison 4 Ultrasound versus sham treatment, Outcome 1 Analgesic requirement.

Comparison 5. Protease complex versus placebo
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Pain not improved159Risk Ratio (M-H, Fixed, 95% CI)0.17 [0.04, 0.74]
2 Breast swelling not improved159Risk Ratio (M-H, Fixed, 95% CI)0.34 [0.15, 0.79]
3 Overall rating of recovery (no change or worse)159Risk Ratio (M-H, Fixed, 95% CI)0.26 [0.12, 0.56]
Analysis 5.1.

Comparison 5 Protease complex versus placebo, Outcome 1 Pain not improved.

Analysis 5.2.

Comparison 5 Protease complex versus placebo, Outcome 2 Breast swelling not improved.

Analysis 5.3.

Comparison 5 Protease complex versus placebo, Outcome 3 Overall rating of recovery (no change or worse).

Comparison 6. Oxytocin versus placebo
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Symptoms not subsided after three days of treatment145Risk Ratio (M-H, Fixed, 95% CI)3.13 [0.68, 14.44]
Analysis 6.1.

Comparison 6 Oxytocin versus placebo, Outcome 1 Symptoms not subsided after three days of treatment.

Comparison 7. Serrapeptase versus placebo
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Slight or no improvement in breast engorgement170Risk Ratio (M-H, Fixed, 95% CI)0.36 [0.14, 0.88]
2 Slight or no improvement in breast swelling170Risk Ratio (M-H, Fixed, 95% CI)0.75 [0.36, 1.55]
3 Slight or no improvement in breast pain170Risk Ratio (M-H, Fixed, 95% CI)0.56 [0.21, 1.49]
Analysis 7.1.

Comparison 7 Serrapeptase versus placebo, Outcome 1 Slight or no improvement in breast engorgement.

Analysis 7.2.

Comparison 7 Serrapeptase versus placebo, Outcome 2 Slight or no improvement in breast swelling.

Analysis 7.3.

Comparison 7 Serrapeptase versus placebo, Outcome 3 Slight or no improvement in breast pain.

What's new

DateEventDescription
1 July 2016AmendedCorrected typographical error and updated affiliation for Contact person.

History

DateEventDescription
30 June 2015New citation required but conclusions have not changedFive new trials included, the conclusions remain unchanged.
30 June 2015New search has been performed

Search updated. Five new trials included (Ahmadi 2011; Batista 2014; Chiu 2010; Kee 1989; Roberts 1998). One of these was previously excluded (Kee 1989) and one that was in 'Awaiting classification' has been included (Roberts 1998).

Methods updated, four new outcomes added and the background has been revised. A 'Summary of findings' table has been added.

23 September 2008AmendedConverted to new review format.

Contributions of authors

Lindeka Mangesi and Irena Zakarija-Grkovic independently assessed study eligibility and carried out data extraction and assessment of risk of bias. The two review authors equally contributed to the update of this review.

Declarations of interest

None known.

Sources of support

Internal sources

  • Cochrane Croatia, Croatia.

    Irena Zakarija-Grkovic was supported by Cochrane Croatia and the Campbell and Cochrane Equity Methods Group

External sources

  • South African Cochrane Centre, South Africa.

    Lindeka Mangesi was supported by South African Cochrane Centre.

Differences between protocol and review

The protocol Methods section has been updated. The following outcomes, which were not in the original protocol, were added because they had not been adequately addressed in the previous version of the review, and were felt to be important for women with breast engorgement.

Primary outcomes: breast pain, breast induration/hardness, breast swelling, breast engorgement.

Secondary outcome: pyrexia (as defined by trial authors) was added to replace temperature higher than 38 degrees celsius.

Methods for GRADE assessment of the quality of the evidence have been added for this update and a 'Summary of findings' table has been incorporated.

Due to the lack of trials and the way in which outcomes were assessed and reported in these trials we were unable to carry out some of our pre-specified methods.

Data were not presented in a way that allowed us to include them in the data tables. We were unable to combine results in meta-analyses or investigate subgroup analysis and assessment of heterogeneity. The small number of included studies with diverse interventions prevented us from carrying out meaningful sensitivity analysis.

For this version of the review we did not identify any cluster-randomised trials.

Notes

This review was not updated earlier due to scarce availability of new evidence; hence conducting a review earlier may have been unnecessary and wasteful.

Characteristics of studies

Characteristics of included studies [ordered by study ID]

Ahmadi 2011

MethodsRandomised controlled trial.
Participants

70 ˝lactating women with breast engorgement˝ who were referred to Gha'em Hospital in Fars, Iran.

Exclusion criteria: mothers with a breast abscess, fever (defined as T > 38°C), sore/cracked nipples, heart disease, fracture in the shoulder region, history of breast surgery, use of traditional herbal remedies for breast engorgement and mothers who did not want to take part in the study.

Interventions

Intervention group (35 participants): acupressure, using hand massage, was applied simultaneously to both breasts for 2 min, followed by a 30-second rest. This was repeated for a total of 20 min and performed twice a day, on 2 consecutive days (a total of 4 times over 2 days).

Control group (35 participants): hot (43-46°C) and cold (10-18° C) compresses were applied intermittently (2 min each) to both breasts simultaneously for 20 min, twice a day, on 2 consecutive days (a total of 4 times over 2 days).

OutcomesBreast engorgement severity index based on degree of breast tension, erythema and pain.
NotesThe study uses individual breasts as the unit of analysis.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskThe paper only states that the 70 women were randomly assigned to 1 intervention or the other in a way that would create 2 intervention groups of 35 each but method of sequence generation is not specified.
Allocation concealment (selection bias)Unclear riskAllocation concealment is not described.
Blinding (performance bias and detection bias)
Women
High riskThe type of intervention did not allow blinding of women.
Blinding (performance bias and detection bias)
Clinical staff
High riskThe type of intervention did not allow blinding of clinical staff.
Blinding of outcome assessment (detection bias)High riskThe outcome assessor based results on a "breast engorgement checklist", but no blinding was done.
Incomplete outcome data (attrition bias)
All outcomes
Low riskNo missing outcome data - all patients were followed up.
Selective reporting (reporting bias)Low riskThe results are strictly based on the authors' pre-made checklist.
Other biasLow riskNo other bias identified. Baseline characteristics (education, career, parity, type of birth) of intervention and control groups very similar.

Batista 2014

MethodsQuasi-randomised controlled trial.
Participants

16 women who sought care for engorgement at the Human Milk Bank of the Hospital Universitario Evangelico de Curitiba, Curitiba, Brazil.

Inclusion criteria: women aged 18 or over who were between 3 and 10 days postpartum with moderate and/or intense bilateral engorgement, regardless of location in the breast.

Exclusion criteria: women with a history of mammoplasty and/or breast prosthesis; use of synthetic oxytocin; use of analgesics in the 6 hours prior to the study; use of cream or talc on the breasts on the exam day; having had a bath up until an hour before the study; exposure to sunlight or light in the 2 hours before the study; history of a palpable or non-palpable breast lesion; previous history of lactational mastitis; obstructive glandular engorgement; tissue integrity impaired in any region of the breast; unwilling to participate.

Interventions

Intervention group (8 participants): 1 min of electromechanical breast massage followed by mechanical pumping, if softening of the breast occurred. If no softening occurred following initial massage, then massager applied for a further 2 min before pumping. The domestically manufactured, vibro-therapeutic massager under the trademark 'Physical' was used; whereas for milk expression a 'Medela' pump in high vibration mode, at maximum suction, was applied, first to the hands of the participant and subsequently, to their breasts.

Control group (8 participants): 1 min of manual breast massage followed by manual pumping, if softening occurred. If no softening occurred following initial massage, then a further 2 min of manual massage performed prior to pumping.

Outcomes

Temperature of the breasts measured with thermography.

The degree of swelling, breast tenderness and intensity of symptoms were measured before the intervention, to determine inclusion eligibility, but, unfortunately, they were not measured post-intervention.

Notes

No information was provided on the massage technique used nor on the duration of pumping (milk expression).

No statement on potential conflict of interest or source of funding is provided.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)High risk˝The investigator flipped a coin. With the result ˝face˝, the first lactating woman would be in the control group...If it was crown˝˝, the lactating woman belonged to the experimental group...Thus the two methods of treatment were alternated starting from the initial random selection.˝
Allocation concealment (selection bias)High risk˝The two methods of treatment were alternated.˝
Blinding (performance bias and detection bias)
Women
High riskThe types of interventions did not allow blinding of women.
Blinding (performance bias and detection bias)
Clinical staff
High riskThe types of interventions did not allow blinding of clinicians.
Blinding of outcome assessment (detection bias)Unclear riskBlinding of outcome assessors is not mentioned and it is not clear whether the outcome assessor was independent of the clinician performing the intervention.
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskA sample size of 196 women was calculated but only 16 were in the final sample. According to the authors the ˝sample was compromised due to the lack of availability of the instrumentation, the acclimatization period required for application of the thermography protocol, and the lack of signed consent forms˝. It is unclear whether women dropped out before or after study inclusion, and if afterwards, how many belonged to each group.
Selective reporting (reporting bias)High risk˝In the evaluation, two methods were applied: clinical exam and thermographic exam...˝ but only breast temperature is reported pre-and post-intervention. According to the authors, the degree of breast swelling, breast tenderness and intensity of engorgement symptoms were measured pre-intervention but they are not reported in the article. It is unclear whether the measurements were repeated post-intervention. The latter outcomes would have been more useful for assessing the effectiveness of the intervention, as they are common symptoms of breast engorgement, unlike a rise in breast temperature.
Other biasHigh risk

Varying degrees of engorgement among women prior to treatment are alluded to but no data specifically given for study groups.

A sample size of 196 women was calculated but only 16 were in the final sample suggesting that the study is severely underpowered.

Chiu 2010

MethodsRandomised controlled trial. Computer-generated block randomisation list, with block sizes of 4 and 8, used to ensure even distribution of participants (30 in each group).
Participants

60 breastfeeding women recruited from a medical centre in central Taiwan.

Inclusion criteria: a) breast engorgement (diagnosed as having hot, painful, hard breasts; non-flow of milk; abnormal thirst levels; and breast tenderness); b) no high-risk complications both before or following childbirth (˝high risk˝ not defined); and c) willingness to participate.

Interventions

Intervention group (27 participants): short and soft Gua-Sha scraping therapy was applied to acupoints ST16, ST18 and SP17, in the direction of the nipples. In addition, scraping therapy was applied between the engorged breasts to acupoints CV17. Each position was lightly scraped 7 times in 2 cycles before the next breastfeed. Intervention time was 2 +/- 0.5 min.

Control group (27 participants): small towels were immersed in hot water, of 43 ± 2 °C, and then applied to the breasts. This was followed by massage, done using the index and middle fingers in a spiral motion towards the nipples. Intervention time in the control group was 20 ± 2 min.

OutcomesBreast engorgement symptoms based on SBES measured at 5 min and 30 min post-treatment. SBES addresses pain, engorgement and discomfort, measured with a visual analogue scale (0 to 10). Breast and body temperatures (measured with digital infrared thermal imaging system) and vital signs (BP) were recorded at 5 min and 30 min post-treatment.
Notes

The standard deviation of changes from baseline was missing for all variables so we used a correlation coefficient of 0.80 to impute the change-from-baseline standard deviation according to the formula provided in the Cochrane Handbook for Systematic Reviews of Interventions (Ch. 16.1.3.2).

Mild skin redness and elevation was noted in the intervention group but no discomfort was expressed by study participants.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk˝Computer- generated block randomisation list.˝
Allocation concealment (selection bias)Unclear riskNot reported. Author contacted, additional information not provided.
Blinding (performance bias and detection bias)
Women
High risk˝Open trial, i.e., all participants knew to which group they had been assigned.˝
Blinding (performance bias and detection bias)
Clinical staff
High risk˝Open trial˝; ˝the primary investigator handled all interventions.˝
Blinding of outcome assessment (detection bias)Low risk˝All data were collected by a nurse who was blinded to patient group assignments.˝
Incomplete outcome data (attrition bias)
All outcomes
Low riskAuthor contacted to clarify inclusions/exclusions: 60 participants initially recruited of which 30 in the experimental group and 30 in the control group. 6 women were ˝removed˝ from the study due to: fever (n = 2), early discharge (n = 2) and fatigue (n = 2). Final number of participants: 54 (27 in each group). Hence, attrition appears balanced in number and reason across groups.
Selective reporting (reporting bias)Low riskBP results not reported, but least relevant to study objectives.
Other biasLow risk˝The groups showed no statistically significant differences in any variables except for age. No significant differences were found between groups in terms of pretest variables.˝

Ingelman-Sundberg 1953

MethodsQuasi-randomised trial. Allocation by folder numbers.
Participants45 women with pronounced signs of engorgement during the second to the 4th day postpartum. Women were located on a private hospital ward in Stockholm, Sweden.
Interventions

Intervention group (20 participants): oxytocin 2.5 IU given subcutaneously daily to women until breasts became soft.

Control group (25 participants): a corresponding amount of physiological saline was given similarly.

In both groups the baby was allowed to breastfeed from the first day after delivery.

Outcomes

Amount of breast milk produced.

Duration of treatment before the engorgement disappeared.

NotesThere were only limited data we were able to use in data tables. The authors state that the baby was allowed to suckle from the first day after delivery and the volume of milk was measured. The results state that the daily amount of milk produced was the same in both groups, although it was not clear how the amount of milk produced was measured.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)High riskOdd or even folder numbers.
Allocation concealment (selection bias)High riskThere was no allocation concealment. Women were allocated into different groups based on their hospital records.
Blinding (performance bias and detection bias)
Women
Low risk"It was concealed from both patient and doctor whether oxytocin or saline was being used."
Blinding (performance bias and detection bias)
Clinical staff
Low risk"It was concealed from both patient and doctor whether oxytocin or saline was being used."
Blinding of outcome assessment (detection bias)Unclear riskThe article does not mention blinding of outcome assessors.
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskThe study does not mention how incomplete outcome data were addressed.
Selective reporting (reporting bias)Unclear riskThe authors report their outcomes in percentages not in numbers out of the totals; which makes it difficult to determine the denominators.
Other biasLow riskNo other bias identified.

Kee 1989

MethodsDouble-blind randomised controlled trial.
Participants

70 women recruited from a postpartum hospital ward in urban Singapore.

Inclusion criteria: postpartum women with breast engorgement. Diagnosis of breast engorgement was based on some or all of the following: subjective complaint of pain in the breast and objective evidence of breast swelling, induration and impaired lactation.

Interventions

Intervention group (35 women): oral serrapeptase (Danzen), an anti-inflammatory proteolytic enzyme drug derived from serratia E15 (isolated from the silk worm intestine) was administered in a dose of 2 tablets (5 mg per tablet) 3 times a day for 3 days.

Control group (35 women) specially made tablets that were identical in appearance to the Danzen tablets were given according to the same regime.

During the study breastfeeding was encouraged and concomitant breast massage and milk expression was allowed.

Outcomes

Total improvement of breast engorgement.

Improvement of individual symptoms:

◦ improvement of breast induration;

∘ improvement of breast swelling; and

∘ improvement of breast pain.

Notes

The authors gave cumulative percentages in the results section, which the review authors corrected. The study authors reported that breastfeeding was encouraged during the study but they report that only 4 patients in the treatment group and 8 in the placebo breastfed their babies during the study period.

No adverse reactions were reported by any of the patients given Danzen.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskRandomised controlled trial but random sequence generation not adequately described.
Allocation concealment (selection bias)Unclear riskAllocation concealment not defined.
Blinding (performance bias and detection bias)
Women
Low risk"The placebo tablets were specially manufactured for the study and were identical in appearance to Danzen tablets."
Blinding (performance bias and detection bias)
Clinical staff
Low risk"None of the research team was aware of the respective identification during the duration of the study."
Blinding of outcome assessment (detection bias)Low risk"An independent observer, unaware of the groups the patients were in, assessed each symptom and sign daily."
Incomplete outcome data (attrition bias)
All outcomes
Low riskThe authors reported on all outcomes.
Selective reporting (reporting bias)Low riskThe authors reported on all outcomes and all participants.
Other biasUnclear riskRole of sponsor unclear. Presumably provided tested drugs. Possible vested interest may have lead to a risk of bias in favour of tested drug.

Kvist 2004

MethodsRandomised controlled trial.
Participants

88 women attending breastfeeding clinics in the South of Sweden with at least 2 of the following symptoms of breast inflammation: erythema, tension, resistance, pain or pyrexia. Half of the women were within 2 weeks of giving birth.

Exclusion criteria (contraindications for acupuncture treatment): psychiatric illness, haemorrhagic disease, prosthetic heart valves, infections of the skin, hepatitis B or HIV.

Interventions

Group 1 (28 women): usual care, including oxytocin nasal spray at the discretion of attending midwives.

Group 2 (35 women): acupuncture to points HT 3 (heart) and GB 21 (gall bladder).

Group 3 (25 women): acupuncture to points HT 3, GB 21 and SP 6 (spleen).

Acupuncture was carried out by midwives with acupuncture experience.

All 3 groups received advice on interval and duration of breastfeeds, breast emptying and application of unrefined cotton wool.

OutcomesSeverity of symptoms on day 3 expressed as severity index (sum of scores for breast tension, erythema and pain); maternal satisfaction with breastfeeding; breast tissue resistance.
NotesPublished results were not reported in a way that we were able to use in data tables. Results state that there were no differences between groups at day 3, but no original data were presented. We contacted the author for further information; data from the study are no longer available.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk"A total of 150 opaque envelopes, 50 for each group, were prepared with a paper denoting the intervention group and sealed. These were then randomly mixed and the envelopes numbered. The envelopes were identical in weight. For those wishing to take part, the midwife opened an envelope in correct numerical order, in the mothers’ presence."
Allocation concealment (selection bias)Low riskDescribed as sealed opaque envelopes opened by midwives in order.
Blinding (performance bias and detection bias)
Women
High riskNot feasible. "Blinding of participants was not attempted in this study because the practice of sham acupuncture has been questioned for its reliability."
Blinding (performance bias and detection bias)
Clinical staff
High riskNot feasible.
Blinding of outcome assessment (detection bias)High risk˝The treating midwife completed protocols for the mothers' initial visit to the clinic and for every follow-up contact until the mother reported that symptoms had subsided.˝
Incomplete outcome data (attrition bias)
All outcomes
High riskCannot be measured. 88 women randomised. Denominators for results not clear. No post-intervention tables provided. Study was ended prematurely partly due to ˝the realization that the number of patients referred to the doctor for prescription of antibiotics was small".
Selective reporting (reporting bias)High riskBreast tissue resistance was not reported in the results even though a scale was devised to measure it. Non-significant results are mentioned but not reported adequately.
Other biasUnclear riskStudy report not very clear to allow identification of other potential sources of bias.

Kvist 2007

MethodsRandomised, non-blinded 3-arm controlled trial.
Participants

Women attending a hospital breastfeeding clinic in the South of Sweden. 210 cases randomised.

Inclusion criteria: at least 2 of the following symptoms: breast erythema, tension, resistance, pain or pyrexia.

Exclusion criteria (contraindications for acupuncture treatment): psychiatric illness, haemorrhagic disease, prosthetic heart valves, infections of the skin, hepatitis B or HIV.

Interventions

Essential care to everyone: advice on duration and frequency of breastfeeds, advice on breast emptying (manual expression, pumping or warm shower) and application of unrefined cotton wool.

Group 1 (70 women): essential care and oxytocin nasal spray, at the discretion of the clinical staff.

Group 2 (70 women): essential care and acupuncture, avoiding the SP6 site which stimulates oxytocin.

Group 3 (70 women): essential care and acupuncture, including the SP6 site.

The acupuncture was performed by midwives who had completed a course in obstetrical acupuncture and had at least 5 years experience in its use.

OutcomesSeverity index (sum of scores for breast tension, erythema and pain) on days 3, 4 and 5; number of contact days till recovery; maternal satisfaction with breastfeeding on days 3, 4 and 5; need for antipyretics, number of contact days till recovery; residual symptoms after 6 weeks, occurrence of breast abscess, need for antibiotics.
NotesThe authors included 5 women, who were randomised twice because they developed residual symptoms after 6 weeks, to the original 205 participants to give 210 episodes of inflammatory symptoms.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskEnvelopes prepared in advance. These were then randomly mixed and the envelopes numbered.
Allocation concealment (selection bias)Low riskOpaque envelopes were used to allocate women into the 3 groups. "The sequence of group allocation was not known to anyone.˝
Blinding (performance bias and detection bias)
Women
High riskThe nature of the trial did not allow blinding. Women who were getting acupuncture would know their intervention.
Blinding (performance bias and detection bias)
Clinical staff
High riskThe authors do not mention blinding of clinical staff but the nature of the study would not allow blinding of clinical staff.
Blinding of outcome assessment (detection bias)Unclear riskThe authors do not mention blinding of outcome assessors.
Incomplete outcome data (attrition bias)
All outcomes
Low riskThe authors report about drop outs and they report that they did ITT analysis.
Selective reporting (reporting bias)Low riskThe authors reported on all pre-specified outcomes.
Other biasLow riskNo other bias identified.

McLachlan 1991

MethodsRandomised double-blind, placebo-controlled trial. Analysis for breasts rather than women.
Participants

197 engorged breasts from 109 women who were referred to the physiotherapist for treatment of breast engorgement.

Exclusion criteria: spoken or written English insufficient for informed consent; breast implants.

Interventions

Intervention breast: Medtron model P300 ultrasound machine used with aquasonic ultrasound transmission gel as coupling agent. Intensity was adjusted to give a comfortable warmth; application head massaged over breast towards areola; firmer pressure used on inwards stroke; duration of treatment ranged from 8 min for A cup to 15 min for a breast of DD or greater cup size.

Control breast: ultrasound machine of identical appearance used in the same way as described above; the control machine had the crystal removed and replaced with a resistor to produce surface heat only. Participants were divided into 3 groups: group 1 (22 women) - both breasts received ultrasound; group 2 (23 women) - both breasts received sham treatment; group 3 (64 women) - 1 breast received ultrasound and 1 breast received sham treatment.

OutcomesPain using a visual analogue scale, hardness using a visual analogue scale, hardness using a digital tonometer. Outcomes measured before and after treatment, prior to breastfeed.
NotesEach breast, instead of an individual woman was the unit of analysis. The machines were labelled as A and B and were changed weekly by someone blind to allocation of women.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk"Balanced block randomisation sequence."
Allocation concealment (selection bias)Unclear riskThe authors do not mention allocation concealment.
Blinding (performance bias and detection bias)
Women
Low riskWomen did not know which treatment they were getting. "The serial numbers of the machines were covered and the machines were labelled A and B. Labels were changed weekly by the Head of Department who had no role in the ultrasound treatment and did not hold the trial log book."
Blinding (performance bias and detection bias)
Clinical staff
Low risk"The serial numbers of the machines were covered and the machines were labelled A and B. Labels were changed weekly by the Head of Department who had no role in the ultrasound treatment and did not hold the trial log book. The woman's name was given to the clerical officer who held the trial log book. She informed the treating physiotherapist which machine to use. (A or B)."
Blinding of outcome assessment (detection bias)Low riskThe outcome assessor was blinded to the groups the women were in.
Incomplete outcome data (attrition bias)
All outcomes
High riskThe authors mentioned that 3 women were lost to follow-up but they did not say how that was handled.
Selective reporting (reporting bias)Low riskThe authors reported all the pre-specified outcomes.
Other biasHigh riskResults were very difficult to interpret as analysis was by breast. The authors also state that when the visual analogue scale was used, it was not always easy for women to make a clear distinction between the left and the right breast.

Murata 1965

MethodsQuasi-randomised trial. Women allocated to different groups on alternate days. Experimental group on even number days and placebo on odd number days.
Participants59 women presenting with breast engorgement (˝mammal swelling or induration˝...˝complaining of pain or tenderness˝) on 3rd to 5th day post-delivery.
Interventions

Intervention group (35 women): day 1: 2 tablets of protease complex, an enteric-coated tablet consisting of bromelain and trypsin, taken 4 times a day (after each meal and before bed time); day 2 and 3: 1 tablet 4 times a day; total of 16 tablets.

Control group (24 women): lactose containing placebo tablets given according to the above regime.

OutcomesSwelling and pain on the afternoon of the 4th day; maternal opinion of treatment; size of breast; shape of nipple; coagulation, prothrombin and bleeding time.
Notes

It was not clear whether all women were breastfeeding. The outcomes were measured using grades according to the degree of improvement of symptoms. In situations where there was no change the grade allocated was 0, where the symptoms became worse, the grade was - 1, in cases where there was a 1 stage improvement the grade given was 1 and where there was a 2 stage improvement, the grade was 2.

No change was detected before and after treatment in regard to coagulation, prothrombin and bleeding time. No complaints were made in regards to gastro-intestinal troubles or poor uterine involution.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)High riskQuasi-randomisation, allocation by day of the week. This method introduced bias in the way the participants were allocated to different groups.
Allocation concealment (selection bias)High riskGroup allocation could be anticipated in advance as it was known which arm of the study was allocated to which day of the week.
Blinding (performance bias and detection bias)
Women
Unclear riskThe study was placebo-controlled but the authors do not mention whether the placebo was identical to the treatment or if it was easy for women to see what they were getting.
Blinding (performance bias and detection bias)
Clinical staff
Unclear riskThere is no mention of blinding of the clinician who administered the treatment.
Blinding of outcome assessment (detection bias)Low risk2 outcome assessors recorded the change in swelling and pain on the 4th day and were not informed as to which participant belonged to which group.
Incomplete outcome data (attrition bias)
All outcomes
Low riskThere were no exclusions and no losses to follow-up.
Selective reporting (reporting bias)Low riskThe authors reported on all pre-specified outcomes.
Other biasUnclear riskProtease complex tablet was supplied by Mochida Pharmaceutical Company under the trademark 'Kimotab'. Possible vested interest may have lead to a risk of bias in favour of tested drug.

Roberts 1995

MethodsRandom assignment to 2 treatment groups.
Participants

28 lactating women with breast engorgement. Inpatients recruited from 2 hospitals in Darwin, Australia, usually on the 3rd day postpartum.

Inclusion criteria: lactation and engorgement defined as ˝hard, very warm, painful breasts, with difficulty feeding", according to the professional judgment of the midwives caring for them.

Exclusion criteria: Aboriginal women.

Interventions

Group 1: chilled cabbage leaves were placed on the right breast and room temperature cabbage leaves were placed on the left breast.

Group 2: cabbage leaves placed in reverse order.

Cabbage leaves applied between feedings and left on for 2 hours. Cabbage leaves, from common green cabbages (Brassica oleracea), were prepared by stripping out the large vein, cutting a hole for the nipple, rinsing, and chilling or leaving at room temperature.

OutcomesPain: pre-treatment measurement; post-treatment measurement 2 hours later.
NotesThis was a convenience sample of lactating women with breast engorgement. All women had both treatments and analyses were for individual breasts rather than for women. As breasts are not independent, results are very difficult to interpret. Pre-test assessments were for 28 women whereas post-test assessments were for 56 breasts. Data were not in a form in which we were able to enter them into data tables.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot described.
Allocation concealment (selection bias)Unclear riskThe authors did not state how allocation concealment was done.
Blinding (performance bias and detection bias)
Women
High riskBlinding of participants was not feasible. All women had both treatments - 1 on each breast and the treatments were not identical as 1 was cold and 1 was room temperature cabbage leaves.
Blinding (performance bias and detection bias)
Clinical staff
High riskBlinding was not feasible as women either received cold or room temperature cabbage leaves.
Blinding of outcome assessment (detection bias)High riskWomen were assessing their breast on a visual analogue scale and midwives were supervising.
Incomplete outcome data (attrition bias)
All outcomes
Low riskThe authors reported on all participants included in the study.
Selective reporting (reporting bias)Low riskThe authors reported on all outcomes.
Other biasHigh riskAnalysis was by breast rather than by women. Breast are unlikely to be independent, especially in terms of outcomes reported in this study. As mentioned in McLachlan 1991, when a visual analogue scale was used, it was not always easy for women to make a clear distinction between the left and the right breast.

Roberts 1995a

MethodsQuasi-randomised trial (breasts rather than women were the unit of analysis).
Participants

34 lactating women located on postnatal wards in 2 Australian hospitals.

Inclusion criteria: non-Aboriginal, lactating, suffering from breast engorgement (hard, warm, painful breasts, with difficulty feeding), according to the professional judgement of the midwives caring for them.

Interventions

Group 1 (even hospital registration numbers): chilled gel pack on the right breast and chilled cabbage leaves on the left breast.

Group 2 (odd hospital registration numbers): opposite to above.

Leaves from common green cabbages were prepared by stripping out the large vein, cutting a hole for the nipple, rinsing and chilling.

Breast-shaped gel pack in small, medium, and large sizes were designed by the researcher to fit under the brassiere, covering the breast except for the nipple area.

Treatment left on breasts for up to 8 hours, with mothers renewing the cabbage leaves and gel packs ad lib, usually every 2 to 4 hours.

OutcomesPre and post-test pain rating for each breast rated on a "pain ruler" (a visual analogue scale with numbers from 0-10, labelled with descriptions 0 = no pain, 5 = moderate pain, and 10 = excruciating pain). Descriptive data about engorgement were also collected.
NotesAnalysis was at the breast level and results were at high risk of bias and difficult to interpret. We have not been able to included data in the data tables.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)High riskQuasi-randomisation (by hospital number).
Allocation concealment (selection bias)Unclear riskThe authors did not mention allocation concealment.
Blinding (performance bias and detection bias)
Women
High riskThe nature of the study did not allow blinding of women.
Blinding (performance bias and detection bias)
Clinical staff
High riskThe nature of the study did not allow blinding of clinicians.
Blinding of outcome assessment (detection bias)High riskParticipants rated outcomes in a self-administered questionnaire. Given that visibly different interventions were placed on each breast blinding of participants/outcome assessors was not possible.
Incomplete outcome data (attrition bias)
All outcomes
Low riskThe authors reported on all outcomes.
Selective reporting (reporting bias)Low riskNo other identified bias.
Other biasHigh riskThe data were analysed at the breast level with no adjustment for the non-independence of breasts. As mentioned in McLachlan 1991, when the visual analogue scale was used, it was not always easy for women to make a clear distinction between the left and right breast.

Roberts 1998

MethodsDouble-blind randomised controlled trial.
Participants

39 lactating, postpartum women with breast engorgement recruited from postnatal wards at Royal Darwin Hospital and Darwin Private Hospital, Australia. Breast engorgement defined as hard, warm, painful breasts with difficulty feeding.

Exclusion criteria: Aboriginal women (tend to have less breast engorgement), women allergic to roses or the cabbage family of plants.

Majority were multiparas with prior breastfeeding experience, who reported the appearance of engorgement symptoms on day 3 postpartum. Significantly more primiparas were in the intervention group.

Interventions

Intervention group (21 women): base cream with 1% cabbage leaf extract (according to British Pharmacopoeia formulation).

Control group (18 women): base/placebo cream only.

Rosewater added to both creams to camouflage residual odour of cabbage.

1 tube of cream was applied liberally to both breasts and left on for 2 hours. The 2-hour period was chosen since cabbage leaves had been shown to act within this period of time, and it could be done within the inter-feeding period.

Mothers were asked to refrain from showers, analgesia and feeding the baby during this period.

Outcomes

Pain, using Bourbonnais pain scale (a visual analogue scale).

Chest circumference, using plastic tape measure.

Degree of hardness, using Roberts durometer.

Degree of engorgement, using Hill and Humenick Breast Engorgement Scale.

Outcomes measured at baseline, 2 hours after application of cream and following subsequent breastfeed.

Notes

Authors were contacted to clarify method of cream application, i.e. to elucidate whether application method (e.g. massage) contributed to treatment effect. According to authors ˝the cream was lightly rubbed in, not massaged, just enough pressure to have the cream absorbed˝.

Authors were also contacted to confirm that results shown in Table 3 refer to post-test measurements (not stated in manuscript), and to check whether there were any significant differences between experimental and control groups for pretest values (given as a combined measure, in Table 4). Precise data on the latter could not be provided, since Australian regulations require data be kept for 5 years only post-publication, but according to trial authors no differences were detected.

The authors report that breastfeeding had a better effect than application of cream in relieving discomfort and decreasing tissue hardness.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk˝Randomised assignment list generated using coin toss.˝
Allocation concealment (selection bias)Unclear risk˝Group assignments were placed in sealed envelopes˝ but type of envelope not stated (transparent or opaque).
Blinding (performance bias and detection bias)
Women
Low riskWomen did not know which cream they were using as the creams were identical in colour and odour.
Blinding (performance bias and detection bias)
Clinical staff
Low riskThe same midwife applied the cream and performed the measurements. The midwife was however blinded to the groups the women were in.
Blinding of outcome assessment (detection bias)Low riskThe midwife who assessed the outcomes was blinded to the allocations.
Incomplete outcome data (attrition bias)
All outcomes
Low riskNo loss of data.
Selective reporting (reporting bias)Unclear riskAll outcomes were reported but in a form that could not be easily interpreted. Pre-test measurements for each outcome were given as a single value, i.e. for both groups combined, so change in outcome measures could not be accurately calculated.
Other biasHigh riskA significant imbalance in primiparas at baseline (P = 0.047) may have been due to chance but may also have been due to possible allocation concealment bias or compromised blinding.

Robson 1990

  1. a

    BP: blood pressure
    ITT: intention-to-treat
    IU: international unit(s)
    min: minutes
    SBES: subjective breast engorgement scale

MethodsRandomised controlled trial.
Participants

88 breastfeeding mothers with "varying degrees" of breast engorgement, all mothers had a caesarean section.

Exclusion criteria: oriental ethnic background (it is not clear how many women were excluded for this reason).

Interventions

Intervention group: breast-shaped cold packs worn 15-20 min after 2 consecutive feeds.

Control group: routine care which encouraged the use of supportive bras, warm compresses. manual expression/pumping of breasts, demand feeding and night time feeding, with intervals between feeds not being longer than 5 hours and each feed taking 30 min to 1 hour.

Outcomes

Pre- versus post-test pain scores. Scores were not reported in a way in which we were able to include them in data tables. We have briefly summarised the results in the text of the review.

Transfer of milk.

Degree of engorgement.

NotesThis study is at high risk of bias. Women in the intervention group who were most distressed were moved into the control group, and those in the control group who wanted packs were moved to the intervention group.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)High riskTable of random numbers generated but randomisation sequence was not observed. 8/88 women were not allocated according to randomisation schedule but according to preferred treatment arm.
Allocation concealment (selection bias)Unclear riskThe authors did not make mention of allocation concealment.
Blinding (performance bias and detection bias)
Women
High riskThe nature of the study did not allow blinding of women.
Blinding (performance bias and detection bias)
Clinical staff
High riskThe nature of the study did not allow blinding of clinical staff.
Blinding of outcome assessment (detection bias)High riskA record of each participant was kept so that data could be analysed without their results.
Incomplete outcome data (attrition bias)
All outcomes
High riskThere were serious protocol deviations and no ITT analysis.
Selective reporting (reporting bias)Low riskThe authors reported on all pre-specified outcomes.
Other biasHigh riskThere was considerable baseline imbalance. Women in the control groups had much lower pretest pain scores. This may be due to the fact that 3 women with the most severe symptoms were moved out of the control group and into the intervention group. There was no ITT analysis.

Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion
  1. a

    hrs: hours
    RCT: randomised controlled trial

Booker 1970This study focused on the suppression of lactation in women who did not intend to breastfeed.
Filteau 1999This study was examining interventions to prevent breast engorgement. Women in 3 villages were assigned 3 different treatments.
Garry 1956This study focused on an intervention for "drying up breasts" in women who did not intend to breastfeed.
King 1958This study focused on an intervention to suppress lactation in women who did not intend to breastfeed.
Nikodem 1993This study included 120 women on postnatal wards of a Johannesburg hospital, South Africa. Women were recruited 72 hrs after delivery. Women in the intervention group received cabbage leaves to their breasts versus routine care (˝breast exercises˝) in the control group. The study was excluded as only approximately half of the sample perceived that they had symptoms of breast engorgement at baseline assessment. Cabbage leaves were therefore used as an intervention to prevent, as well as to treat, engorgement. Separate figures were not available for those women that had engorgement at the outset and were treated for symptoms. Results of this study suggested that women in the intervention group were more likely than those in the usual care group to be exclusively breastfeeding at 6 weeks (76% versus 58%).
Phillips 1975This study only included women who had chosen not to breastfeed.
Roser 1966It was not clear whether this study was an RCT. This study focused on an intervention to suppress lactation in women who did not intend to breastfeed; the treatment was commenced during labour, before the onset of any symptoms of breast engorgement.
Ryan 1962In this study women that were breastfeeding were excluded.The study focused on an intervention to suppress lactation in women who did not intend to breastfeed.
Stenchever 1962This study focused on an intervention to suppress lactation in women who did not intend to breastfeed.

Ancillary