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Immersion in water during labour and birth

  • Review
  • Intervention

Authors


Abstract

Background

Water immersion during labour and birth is increasingly popular and is becoming widely accepted across many countries, and particularly in midwifery-led care settings. However, there are concerns around neonatal water inhalation, increased requirement for admission to neonatal intensive care unit (NICU), maternal and/or neonatal infection, and obstetric anal sphincter injuries (OASIS). This is an update of a review last published in 2011.

Objectives

To assess the effects of water immersion during labour and/or birth (first, second and third stage of labour) on women and their infants.

Search methods

We searched Cochrane Pregnancy and Childbirth’s Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (18 July 2017), and reference lists of retrieved trials.

Selection criteria

We included randomised controlled trials (RCTs) comparing water immersion with no immersion, or other non-pharmacological forms of pain management during labour and/or birth in healthy low-risk women at term gestation with a singleton fetus. Quasi-RCTs and cluster-RCTs were eligible for inclusion but none were identified. Cross-over trials were not eligible for inclusion.

Data collection and analysis

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. Two review authors assessed the quality of the evidence using the GRADE approach.

Main results

This review includes 15 trials conducted between 1990 and 2015 (3663 women): eight involved water immersion during the first stage of labour; two during the second stage only; four during the first and second stages of labour, and one comparing early versus late immersion during the first stage of labour. No trials evaluated different baths/pools, or third-stage labour management. All trials were undertaken in a hospital labour ward setting, with a varying degree of medical intervention considered as routine practice. No study was carried out in a midwifery-led care setting. Most trial authors did not specify the parity of women. Trials were subject to varying degrees of bias: the intervention could not be blinded and there was a lack of information about randomisation, and whether analyses were undertaken by intention-to-treat.

Immersion in water versus no immersion (first stage of labour)

There is probably little or no difference in spontaneous vaginal birth between immersion and no immersion (83% versus 82%; risk ratio (RR) 1.01, 95% confidence interval (CI) 0.97 to 1.04; 6 trials; 2559 women; moderate-quality evidence); instrumental vaginal birth (12% versus 14%; RR 0.86, 95% CI 0.70 to 1.05; 6 trials; 2559 women; low-quality evidence); and caesarean section (5% versus 4%; RR 1.27, 95% CI 0.91 to 1.79; 7 trials; 2652 women; low-quality evidence). There is insufficient evidence to determine the effect of immersion on estimated blood loss (mean difference (MD) -14.33 mL, 95% CI -63.03 to 34.37; 2 trials; 153 women; very low-quality evidence) and third- or fourth-degree tears (3% versus 3%; RR 1.36, 95% CI 0.85 to 2.18; 4 trials; 2341 women; moderate-quality evidence). There was a small reduction in the risk of using regional analgesia for women allocated to water immersion from 43% to 39% (RR 0.91, 95% CI 0.83 to 0.99; 5 trials; 2439 women; moderate-quality evidence). Perinatal deaths were not reported, and there is insufficient evidence to determine the impact on neonatal intensive care unit (NICU) admissions (6% versus 6%; average RR 1.30, 95% CI 0.42 to 3.97; 2 trials; 1511 infants; I² = 36%; low-quality evidence), or on neonatal infection rates (1% versus 1%; RR 2.00, 95% CI 0.50 to 7.94; 5 trials; 1295 infants; very low-quality evidence).

Immersion in water versus no immersion (second stage of labour)

There were no clear differences between groups for spontaneous vaginal birth (98% versus 97%; RR 1.02, 95% CI 0.96 to 1.08; 120 women; 1 trial; low-quality evidence); instrumental vaginal birth (2% versus 2%; RR 1.00, 95% CI 0.06 to 15.62; 1 trial; 120 women; very low-quality evidence); caesarean section (0% versus 2%; RR 0.33, 95% CI 0.01 to 8.02; 1 trial; 120 women; very low-quality evidence), and NICU admissions (8% versus 11%; RR 0.78, 95% CI 0.38 to 1.59; 2 trials; 291 women; very low-quality evidence). Use of regional analgesia was not relevant to the second stage of labour. Third- or fourth-degree tears, and estimated blood loss were not reported in either trial. No trial reported neonatal infection but did report neonatal temperature less than 36.2°C at birth (9% versus 9%; RR 0.98, 95% CI 0.30 to 3.20; 1 trial; 109 infants; very low-quality evidence), greater than 37.5°C at birth (15% versus 6%; RR 2.62, 95% CI 0.73 to 9.35; 1 trial; 109 infants; very low-quality evidence), and fever reported in first week (2% versus 5%; RR 0.53, 95% CI 0.10 to 2.82; 1 trial; 171 infants; very low-quality evidence), with no clear effect between groups being observed. One perinatal death occurred in the immersion group in one trial (RR 3.00, 95% CI 0.12 to 72.20; 1 trial; 120 infants; very low-quality evidence). The infant was born to a mother with HIV and the cause of death was deemed to be intrauterine infection.

There is no evidence of increased adverse effects to the baby or woman from either the first or second stage of labour.

Only one trial (200 women) compared early and late entry into the water and there were insufficient data to show any clear differences.

Authors' conclusions

In healthy women at low risk of complications there is moderate to low-quality evidence that water immersion during the first stage of labour probably has little effect on mode of birth or perineal trauma, but may reduce the use of regional analgesia. The evidence for immersion during the second stage of labour is limited and does not show clear differences on maternal or neonatal outcomes intensive care. There is no evidence of increased adverse effects to the fetus/neonate or woman from labouring or giving birth in water. Available evidence is limited by clinical variability and heterogeneity across trials, and no trial has been conducted in a midwifery-led setting.

Plain language summary

Immersion in water in labour and birth

What is the issue?

To assess the effects of water immersion (waterbirth) during labour and/or birth (first, second and third stage of labour) on women and their infants.

Why is this important?

Many women choose to labour and give birth in water (water immersion) and this practice is becoming more popular in many countries, particularly in midwifery-led units. Therefore, it is important to understand more about the benefits of water immersion in labour and birth for women and their newborns, along with any risks.

It is important to examine whether immersion in water during the first and/or the second stage of labour has the potential to maximise women's ability to manage labour pain, and to have a normal birth without increasing the risk of an adverse (harmful) event. Adverse events might be an increased risk of infection for women and/or their newborn; an increased likelihood of a serious tear to the perineum (the area between anus and vagina), and it may make estimating blood loss more difficult in the event of a haemorrhage. In assessing the benefits, we consider well-being to cover both physical and psychological health.

What evidence did we find?

We included 15 trials (3663 women). All the trials compared immersion in water with no immersion in water: eight during the first stage of labour, two during the second stage of labour (waterbirth) only, four during the first and second stages of labour, and one early versus late immersion during the first stage of labour. The evidence was of moderate to very low quality. No trial compared immersion in water with other forms of pain management.

Water immersion during the first stage of labour probably results in fewer women having an epidural, but probably makes little or no difference to the number of women who have a normal vaginal birth, instrumental birth, caesarean section or a serious perineal tear. We are uncertain about the effect on the amount of blood loss after birth because the quality of the evidence was very low. Labouring in water also may make little or no difference to babies being admitted to neonatal intensive care unit (NICU) or developing infections. Stillbirths and baby deaths were not reported.

Two trials compared water immersion during the second stage (birth) with no immersion. We found that immersion may make little or no difference in numbers of women who have a normal vaginal birth. It is uncertain whether immersion makes any difference to instrumental vaginal births, caesarean sections, numbers of babies admitted to NICU, babies' temperatures at birth and fever in babies during the first week, because the quality of the evidence was found to be very low for all of these outcomes. Epidurals were not relevant to this stage of labour. Serious perineal tears and blood loss after birth were not reported in either trial.

Only one trial (200 women) compared women who got into the water early and late in their labour but there was not enough information to show any clear differences between the groups.

What does this mean?

Labouring in water may reduce the number of women having an epidural. Giving birth in water did not appear to affect mode of birth, or the number of women having a serious perineal tear. This review found no evidence that labouring in water increases the risk of an adverse outcome for women or their newborns. The trials varied in quality and further research is needed particularly for waterbirth and its use in birth settings outside hospital labour wards before we can be more certain of these effects. Research is also needed about women’s and caregivers experiences of labour and birth in water.

平易な要約

分娩進行中や分娩時に水に浸かること

論点

分娩進行中と分娩時(分娩第1期、第2期と分娩第3期)、もしくはどちらかに水に浸かる(水中分娩)ことの母児に関する効果を評価すること。

重要である理由

多くの女性が分娩進行中や分娩時を水中で過ごすこと(水に浸かること)を選択し、この実践は、特に助産師主導のユニットを中心に、多くの国で人気が高まっている。したがって、分娩進行中や分娩時に水に浸かることによる女性と新生児の利点について、リスクとともに理解することは重要である。

分娩第1期と第2期、もしくはどちらかの時期に水に浸かることは、陣痛に対処する女性自身の能力を最大限に引き出し、有害事象の発生が増加することなく正常分娩をもたらすのかどうかを調べることは重要である。母体と新生児、もしくはどちらかの感染の発生や、重度の会陰(肛門と腟の間の部位)の裂傷を生じる可能性などの有害事象が増加する可能性や、大出血が生じた際に、出血量の推測が困難になる可能性がある。メリットを評価する際、身体的と心理的な健康の両方の健康状態を考慮する。

得られたエビデンス

15 試験 (3663人) を組み入れた。全ての試験は水に浸からないことと、水に浸かることの比較だった。8試験は分娩第1期、2試験は分娩第2期(水中分娩)のみ、4試験は分娩第1期と分娩第2期で、1試験は分娩第1期の前半と後半に水に浸かることの比較だった。エビデンスの質は中等度から低度だった。水に浸かることと、他の疼痛管理方法を比較した試験はなかった。

分娩第1期に水に浸かることは硬膜外麻酔を使用する女性の数を減らす結果となったが、正常分娩、器械分娩、帝王切開や重度の会陰裂傷の発生頻度には、ほどんどもしくは全く差はなかった。エビデンスの質が非常に低度だったため、分娩後の出血量に関する効果については不確実だった。分娩進行中を水中で過ごすことについても、新生児集中治療室(NICU)への入室や感染症を発症した児の数に、ほとんどもしくは全く差はなかった。死産や新生児死亡についての報告はなかった。

2試験が分娩第2期(分娩時)に水に浸かることと、浸からないことの比較を行っていた。水に浸かることは、正常経腟分娩となる女性の数にほとんど、もしくは全く差はなかった。エビデンスの質はとても低度であったため、器械分娩、帝王切開、NICUへ入室した新生児の数、分娩時の児の体温や生後1週間の児の発熱のアウトカムについて、水に浸かることにより差をもたらすかどうかは不確実である。硬膜外麻酔の使用はこの段階の分娩期とは関連がなかった。重度の会陰裂傷や出生後の出血についてはどちらの試験でも報告はなかった。

1つの試験(200人)のみで、分娩進行中の前半もしくは後半に水に浸かることについて比較していたが、群間で明らかな差を示すには十分な情報がなかった。

意味するもの

水中で分娩期を過ごすことは硬膜外麻酔の使用を減らす可能性がある。水中で分娩を行うことにより、分娩方法や重度の会陰裂傷を生じる女性の数に影響はなかった。このレビューでは、水中で分娩期を過ごすことにより、女性や新生児の有害なアウトカムの発生を増加させるかどうかについてのエビデンスは分からなかった。組み入れた試験の質は様々であり、より効果の確実性を得るには、特に水中分娩や病院以外での分娩場所におけるさらなる研究が必要である。分娩進行中や分娩時を水中ですごすことの女性とケア提供者の経験についても研究が必要である。

訳注

《実施組織》増澤祐子、杉山伸子 翻訳 [2018.5.27] 《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、コクラン日本支部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。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。 《CD000111》