Amenorrea de la lactancia para la planificación familiar
Resumen
Antecedentes
Se calcula que alrededor del 40% de los embarazos en el mundo son no planificados y que la mayor parte de ellos son no deseados. Debido a varias razones, que incluyen la dificultad para obtener anticonceptivos, no se utiliza un método anticonceptivo, o éste no es efectivo para evitar estos embarazos. El método de amenorrea de la lactancia (MELA) es un método anticonceptivo en el que se informa a la madre y se la apoya para que utilice la lactancia como método anticonceptivo. El MELA está disponible y accesible para muchas mujeres.
Objetivos
Evaluar la efectividad del MELA, como se define en la declaración del Consenso de Bellagio de 1988, como método anticonceptivo en las mujeres que lactan completamente y que están en amenorrea, mediante tablas de vida de embarazo y menstruación.
Métodos de búsqueda
Se realizaron búsquedas en MEDLINE, EMBASE, POPLINE y LILACS hasta el 10 de octubre 2014; listas de referencias de los estudios; artículos de revisión; libros relacionados con el MELA; resúmenes publicados de conferencias sobre lactancia materna, salud reproductiva; correos electrónicos con los coordinadores de los estudios.
Criterios de selección
De 459 estudios potencialmente relevantes, 159 investigaron el riesgo de embarazo durante el MELA o la amenorrea de la lactancia. Los criterios de inclusión fueron los siguientes: estudio prospectivo; los casos (grupo de intervención) y, si existían, los controles, debían ser sexualmente activas; el embarazo se debía confirmar mediante un examen físico o una prueba de embarazo. Las variables principales de resultado fueron las tasas de menstruación y las tasas de embarazo de la tabla de vida. Se incluyeron 15 estudios que informaron sobre 11 grupos de intervención y tres grupos control. En la actualización de 2007 se identificó un estudio adicional no controlado, y un estudio adicional controlado en esta actualización de 2015.
Obtención y análisis de los datos
Dos autores de la revisión extrajeron los datos de forma independiente, y resolvieron los desacuerdos mediante discusión. Los estudios se analizaron mediante métodos narrativos debido a su heterogeneidad.
Resultados principales
Para el resultado primario, embarazo, dos estudios controlados de usuarias de MELA informaron sobre tasas de embarazo de la tabla de vida a los seis meses de 0,45% y 2,45%, un estudio controlado informó el 5% de embarazos en ausencia de las tasas de tabla de vida por mes, y ocho estudios no controlados de usuarias de MELA informaron sobre tasas de embarazo del 0% al 7,5%. Las tasas de embarazo en la tabla de vida de las mujeres que lactaron completamente y que estaban en amenorrea, pero que no utilizaron métodos anticonceptivos, fueron del 0,88% en un estudio y del 0,9% al 1,2% (intervalo de confianza del 95%: 0,0 a 2,4) en un segundo estudio, según la definición de menstruación utilizada. La tasa de menstruación a los seis meses en todos los estudios varió entre el 11,1 y el 39,4%.
Conclusiones de los autores
No se encontraron diferencias claras en las tasas de embarazo de la tabla de vida entre las mujeres que utilizaron el MELA y recibieron apoyo para hacerlo, y las mujeres en amenorrea que lactaron completamente y no utilizaron método alguno. Debido a que la duración de la amenorrea de la lactancia en las mujeres que utilizan MELA difiere mucho entre las poblaciones estudiadas y es específica de cada una de ellas, no se conoce con certeza si el MELA prolonga la amenorrea de la lactancia.
PICO
Resumen en términos sencillos
Amenorrea de la lactancia para la planificación familiar
El método de amenorrea de la lactancia (MELA) es un método anticonceptivo en el que se informa y apoya a la madre sobre cómo utilizar la lactancia para la anticoncepción. La lactancia sin alimentación suplementaria retrasa el retorno de la fertilidad y los períodos menstruales, lo que constituye una protección normal (fisiológica) contra el embarazo. En esta revisión se ha estudiado la efectividad del MELA como método anticonceptivo en mujeres con lactancia materna completa, en comparación con las mujeres con lactancia materna sin apoyo alguno. No se encontraron diferencias claras en la efectividad (embarazo) entre las mujeres que utilizaron el MELA con apoyo y las mujeres en amenorrea con lactancia materna completa que no utilizaron método alguno. Aparte de lo anterior, se recomienda la lactancia materna como tal desde el punto de vista de la salud pública.
Authors' conclusions
Background
Description of the condition
It is estimated that among the annual 150 million pregnancies in the world, about 40% are unintended and unplanned and that the major part of these are unwanted. Most of these pregnancies occur in low income countries (Alan Guttmacher Institute 1999; Lakha 2006; Trussell 2008; UNFPA 2014). There are several reasons no or ineffective contraception is used to prevent these unplanned pregnancies, including difficulties in obtaining contraceptives.
Description of the intervention
The lactational amenorrhoea method (LAM) is a contraceptive method available and accessible to many women (Family Health 1988; Kennedy 1989). LAM was defined during the 1988 Bellagio Consensus Conference in Italy (Bellagio 1988) as the informed use of breastfeeding as a contraceptive method by a woman who is still amenorrheic and does not feed her baby with supplements for up to six months after delivery. LAM provides more than 98% protection from pregnancy in the first six months postpartum, according to its advocates (Family Health 1988; Kennedy 1989; Kennedy 1992; Labbok 1994). During a second conference in Bellagio in 1995, it was suggested that women choosing and using the LAM had a life table pregnancy rate at six months of less than 2%. This was not based on a systematic review. It was also suggested "in the studies that included the promotion of appropriate breastfeeding practices, the percentages of women still amenorrheic and still fully breastfeeding at six months postpartum were higher than in control groups not receiving such support" (Kennedy 1996; Van Look 1996).
LAM is a 'transitional' form of contraception and is most effective in women planning to breastfeed exclusively during the first six months (Labbok 1997). However, many women choose not to use this method owing to concerns about its efficacy (Lopez‐Martinez 2006), and uptake is low in many countries (Khella 2004). Where LAM is implemented, the information provided to women includes: the physiological mechanism of lactation and its control of reproductive function; the efficacy of LAM as a means of contraception; and the benefits and disadvantages of LAM as a contraceptive method (Lopez‐Martinez 2006; Romero‐Gutierrez 2007). Several studies that have followed up women claiming to use LAM showed that few of the women actually implemented the method or used it correctly (Romero‐Gutierrez 2007; Sebastian 2012; Sipsma 2013).
In a study in Turkey, 34% of the research sample of women with six‐month‐old infants were said to use LAM to prevent pregnancy after childbirth. However, only 17.2% of the women using LAM successfully fulfilled the LAM criteria, with 82.8% not fulfilling one or more of the LAM criteria. The pregnancy rate of the women using 'LAM' was 32.8% (Türk 2010).
How the intervention might work
The suckling stimulus reduces pulsatile secretion of GnRH/LH, thus suppressing ovarian activity (McNeilly 2001).
Why it is important to do this review
Many studies on LAM do not include a control group, thus the quality of these studies varies; it is therefore difficult to support the suggestions of the World Health Organization Task Force on Methods for the Natural Regulation of Fertility, WHO 1999b, and those of Labbok (Labbok 1997). If LAM is effective as a contraceptive in the postpartum period, there may be implications in offering this method for use in low income countries, in particular where access to or the acceptability of other forms of contraception may be limited. In countries where there is no such limitation, LAM should be studied only if its advocation does not hamper the introduction of longer‐term methods of contraception.
Objectives
To determine the efficacy and safety of LAM as a contraceptive method for lactating women during the 0 to 6 months' postpartum period, and to determine all the conditions under which LAM should be used (Stroup 2000). We compared the incidence of menstruation and pregnancy in LAM users to that of recently delivered, fully breastfeeding women who did not use LAM.
Methods
Criteria for considering studies for this review
Types of studies
It is unlikely that all women remember exactly when they stopped breastfeeding, started giving supplementary feeds to their infant, had their first period after childbirth, and resumed sexual activity. We therefore included not only prospective studies, but both controlled and uncontrolled studies (Quandt 1997; Vitzhum 1994).
Types of participants
Sexually active, healthy, fertile women who had recently given birth and practiced the LAM as their only contraceptive method. If women are not sexually active while practicing a family planning method, no pregnancy can occur. We therefore noted if it was mentioned in the included studies if the participants and, if available, the controls were sexually active (including frequency) during the study period (Caldwell 1977; Feyiesetan 1990; Shaaban 2013; Urdry 1993; van de Walle 1993; Visness 1997).
Types of interventions
Women using LAM compared with controls who gave birth recently and were breastfeeding without support.
Types of outcome measures
Primary outcome measures
Pregnancy and 'menstruation' (after being amenorrheic) were primary outcome measures. The studies had to present the number of women per specific month who experienced 'menstruation' or who became pregnant. Pregnancy had to be confirmed by physical examination or by a pregnancy test.
We considered several definitions of being amenorrheic. The original definition used in the Bellagio Consensus Statement ignores any bleeding before the 56th day postpartum (Family Health 1988). However, in 1995 in Bellagio menstruation was defined as the occurrence, after the 56th day postpartum, of "2 consecutive days of bleeding/spotting, or the women's perception that her menses have returned, whichever of the two comes first" (Kennedy 1996). Labbok used definitions of two continuous days of vaginal bleeding that the woman considered similar to a menstrual period or heavier, or two continuous days of spotting and one day of bleeding, or three continuous days of spotting (Labbok 1997). The World Health Organization used four different definitions to mark the end of amenorrhoea (WHO 1999a).
In this systematic review we used three different definitions:
-
We used the original definition of lactational amenorrhoea in fully lactating women, i.e. "ignoring any bleeding before the 56th day postpartum", as standard.
-
Any bleeding (including bleeding within 56 days postpartum but separated from the postpartum bleeding by 10 to 14 days or more).
-
The woman's perception that her menses have returned.
Search methods for identification of studies
Electronic searches
We searched
‐ MEDLINE, EMBASE, POPLINE, and LILACS to 10 October 2014 (Appendix 1);
‐ Cochrane Central Register of Controlled trials (2014)
‐ reference lists of studies, review articles, books related to LAM, published abstracts from breastfeeding and reproductive health conferences.
We had e‐mail contact with study coordinators.
Searching other sources
We also considered studies identified from reference lists and review articles, books related to LAM, and abstracts of conferences. Furthermore, we emailed co‐ordinators of such studies and made enquiries with contraception‐orientated organisations such as the World Health Organization and Population Council. We applied no language restrictions.
Data collection and analysis
Selection of studies
We updated this review in 2015.
Two review authors (CW and Frans Helmerhorst in the original review; CW and Julie Brown in the 2008 update; CW and CM in this update) independently selected the studies according to the pre‐set inclusion criteria. Any disagreements were resolved through discussion. When we identified multiple reports of a study, we used only the original results.
Data extraction and management
One review author performed data extraction, and the second review author checked and recorded the data.
Assessment of risk of bias in included studies
To assess the risk of bias in individual studies we used a modification of a previously published checklist from the National Health Service Centre for Reviews and Dissemination (NHS Centre 2001). Items included were: Did the women enrol at a similar entry point? Were the groups comparable on all important confounding factors? Was follow‐up long enough for the outcomes to occur? Was the drop‐out rate less than 10%? Were the outcomes used clear? Were the presented data clear? We considered age, parity, and length of previous lactational amenorrhoea or breastfeeding as confounders. The period of lactational amenorrhoea tends to be longer for older multiparous women than for younger primiparous women (WHO 1998b). Moreover, older age itself has an influence on fertility, and the consecutive lactational amenorrheic period of these women tends to be longer (Jain 1969). Regarding loss to follow‐up, we used a cut‐off point of 10% in scoring this criterion. Loss to follow‐up can occur for various reasons, such as the mother stopping breastfeeding because of the child’s death, being dissatisfied with LAM, choosing another family planning method, wishing to become pregnant, becoming pregnant, or moving to a place outside the study area.
Unit of analysis issues
There are no unit of analysis issues in this review; all reports presented data per woman.
Dealing with missing data
Where there were insufficient or missing data, we contacted the study's lead author. If no response was forthcoming, we included the study but did not describe the data in the text of the review.
Assessment of heterogeneity
After inclusion, two review authors, using their subjective judgement, assessed heterogeneity of the studies, taking into account study design and comparability of populations, interventions and controls, outcomes, and reported effects. For studies that we considered sufficiently homogeneous, we planned to perform statistical pooling using life table methods; this was not possible and we thus presented a narrative synthesis.
All intervention groups presented in 13 of the studies were different from each other. At least 26 different populations were used: various cultures and nationalities and both urban and rural locations in the same country. Knowing that fertility and the recurrence of menstruation after childbirth are population specific, we found that the populations themselves were not comparable. These differences indicated to us that statistical pooling would not be appropriate and we have instead presented narrative results.
Assessment of reporting biases
We retrieved studies from as many sources as possible. There were not sufficient studies to construct a funnel plot to assess reporting biases.
Data synthesis
Owing to heterogeneity among the included studies, we were unable to perform a meta‐analysis and therefore have described the results in narrative form. We used a single, not multiple, decrement life table technique to present the data (Trussell 1991a). Multiple decrement life tables measure survival (or failure) of individuals or groups over time. This technique is frequently used in contraceptive research to measure the probability of pregnancy or method continuation. In this context, it measures multiple reasons for discontinuation, including pregnancy, hormonal side effects, etc. Single decrement life tables are calculated in the same way as multiple decrement life tables, but at the time of discontinuation they censor individuals who stop using a method for reasons other than the one being measured. They are therefore recommended as the most appropriate method to measure contraceptive outcomes (Trussell 1991a). The life tables presented the number of women per specific month who had a 'menstruation' or who became pregnant.
Subgroup analysis and investigation of heterogeneity
We did not present any subgroup analysis in this review.
Sensitivity analysis
We did not present a sensitivity analysis in this review.
Results
Description of studies
Results of the search
In this updated 2015 review we identified one additional study for inclusion (Shaaban 2013). Thus, from 459 publications (2003 data) identified in the literature, 159 presented original data; 90 were prospective. There were 12 double publications, leaving 78 (2003 data). In 64 (2003 data), one or more inclusion criteria were not fulfilled (no life table rates, sexual activity unknown, no differentiation between full and partial breastfeeding, loss to follow‐up not specified, highly selective studies according to study co‐ordinators). Hence, 15 studies were left, which dealt with 11 original intervention groups and three control groups (2015 data). We included these 15 studies in this systematic review (Cooney 1996; Díaz 1988a; Díaz 1988b; Díaz 1991; Díaz 1992; Egbuonu 2005; Kazi 1995; Labbok 1997; Peréz 1991; Peréz 1992; Ramos 1996; Ravera 1995; Rodríguez 1993; Shaaban 2013; WHO 1999a).
Included studies
See 'Characteristics of included studies'. We identified only three controlled trials (Díaz 1988a; Peréz 1991; Shaaban 2013). However, Díaz presented the data in four separate publications; in three she presented only data about cases (the intervention group), and in one he presented similar data plus data about controls, this suggesting it was a controlled study (Díaz 1988a; Díaz 1988b; Díaz 1991; Díaz 1992). Peréz presented the same cases in two publications, one with controls and one without (Peréz 1991; Peréz 1992). Thus, 11 (15 minus 4) intervention groups (cases) were left and 3 control groups.
Excluded studies
The main reason for excluding studies was the lack of reported life table rates, sexual activity unknown, no differentiation between full and partial breastfeeding, loss to follow‐up not specified, and highly selective studies according to the co‐ordinators of these studies (see 'Characteristics of excluded studies').
Risk of bias in included studies
See 'Characteristics of included studies' and Table 1.
| Trials | Entry point | Confounding of cases | Confounding of controls | Follow‐up length | Dropouts < 10% | Data clear | Endpoints clear | Same population |
| + | Unclear | + | Unclear | + | Unclear | ‐ | ||
| ‐ | Unclear | Unclear | + | + Cases | ‐ | + | ‐ | |
| + | ‐ | + | + | + | ‐ | + | ||
| + | ‐ | + | + | + | + | ‐ | ||
| + | ‐ | + | + | + | Unclear | ‐ | ||
| + | Unclear | Unclear | + | + Cases | ‐ | + | ‐ | |
| + | ‐ | + | + | + | + | ‐ | ||
| + | Unclear | + | Unclear | + | + | ‐ | ||
| ‐ | Unclear | + | + | ‐ | + | ‐ | ||
| + | ‐ | ‐ | + | + | ‐ | Unclear | + | |
| + | Unclear | + | Unclear | + | + | ‐ |
LAM: lactational amenorrhoea method
WHO: World Health Organization
Allocation
In the study of Shaaban (Shaaban 2013), allocation concealment was clear; in two studies, Díaz 1988a and Peréz 1991, allocation concealment was unclear. There was no evidence that allocation concealment had been used in the remainder.
Blinding
There was no blinding to the intervention in any of the studies.
Follow ‐up and exclusions
Follow‐up was acceptable concerning the primary outcome and ranged from six months to one year.
Selective reporting
There was no evidence of selective reporting in any of the studies.
Other potential sources of bias
One of the main sources of bias within this review is the multiple definitions of 'amenorrhoea' that were used. This means there is also considerable selection bias in the type of women enrolled in the studies. In most studies women were included just after delivery. Díaz (Díaz 1988a) and Rodríguez (Rodríguez 1993) started to include women between 6 and 12 weeks after delivery, thus creating a selection bias. The confounders of age were given in all included studies and those regarding parity in all but one (Shaaban 2013). The confounder length of previous lactational amenorrhoea and breastfeeding were not clear in the studies from the WHO (WHO 1999a), Cooney (Cooney 1996), Díaz (Díaz 1988a), Peréz (Peréz 1991), Ravera (Ravera 1995) and Rodríguez (Rodríguez 1993). In the studies by Cooney, Ravera and the WHO the drop‐out rate was more than 10%, but was not specified. For example, Cooney’s study (Cooney 1996) took place during the civil war in Rwanda. The definitions of the endpoints were not clear in the reports by Cooney (Cooney 1996), Labbok (Labbok 1997) and Shaaban 2013. The results were presented in a transparent way in all studies, except for Díaz (Díaz 1988a), Peréz (Peréz 1991) and Rodríguez (Rodríguez 1993). In the study of Shaaban 2013, only women were included having a contact phone number.
Effects of interventions
Pregnancy rate in controlled studies
As already noted, we identified three controlled studies (Díaz 1988a; Peréz 1991; Shaaban 2013). Díaz studied breastfeeding women using an intrauterine device (IUD) as a control group. For the purpose of pregnancy rates, we did not consider these controls to be suitable (none of the women became pregnant). In this controlled study, two different definitions were used to mark the end of amenorrhoea. The standard definition, ignoring any bleeding before day 56 postpartum, gave a cumulative life table pregnancy rate of 2.45 after 6 months. Using the second definition, that is any bleeding marking the end of amenorrhoea, a cumulative life table pregnancy rate of 0.45 was calculated.
Peréz 1991 used the standard definition of amenorrhoea. The life table pregnancy rate was 0.45 (one pregnancy in 1671 woman months accumulated (WMAC)) for the women using the LAM, compared with zero (none in 690 WMAC) for the controls, who were fully breastfeeding, amenorrheic women not using any other method of contraception. In the Shaaban 2013, women counseled on LAM were the cases and women counseled on LAM and emergency contraception (EC) served as controls. The EC was provided with instructions to be used in case one of the prerequisites of LAM expired and sexual relations had occurred. No life tables were given, but 29 pregnancies occurred in the 529 LAM users and 2 in the 529 women using LAM and EC.
Recurrence of 'menstruation' (vaginal blood loss) in controlled studies
We obtained data from the same three controlled studies already noted (Díaz 1988a; Peréz 1991; Shaaban 2013). Díaz found no difference in re‐establishment of 'menstruation' between the intervention and the control groups. Of all fully breastfeeding women (236 cases and 440 controls), 52% were not amenorrheic at 6 months. Peréz found that 56% of the fully nursing women in the intervention group remained amenorrheic at 6 months (life table menstruation rate 18.78), compared with 22% in the control group. The objective of Peréz's study was to assess the impact of a breastfeeding promotion campaign and the acceptance and use of LAM for natural child spacing, not to test the effectiveness of LAM. The LAM users and their healthcare providers received an exceptional amount of support. In the study of Shaaban, about 20% had resumed menstruation at 6 months and only 20% were (almost) exclusively breastfeeding. Shaaban defines "exclusive" or "nearly exclusive" breastfeeding as follows: "breastfeeding the infant at least every 4 h during the daytime and at least every 6 h during nighttime, and not giving the infant other additional liquid, semi‐solid or solid food"; we therefore put the word "almost" between brackets. Life tables were not given Shaaban 2013.
Pregnancy rate in uncontrolled studies
We identified six uncontrolled studies that used the standard LAM definition (Cooney 1996; Egbuonu 2005; Kazi 1995; Labbok 1997; Ramos 1996; Ravera 1995). The number of pregnancies per woman month of LAM use during the first 6 months were according to Kazi 1/131.3 (cumulative pregnancy rate (CPR) 0.58), Ravera 0/432, Cooney 0/1264, Ramos 2/1030.5 (CPR 0.97), and Labbok 5/2718 (CPR 1.5). Egbuonu provided no woman months. It should be noted that the life table pregnancy rates in the multicentre study of Labbok varied from 0 to 7.5 per site.
In Ramos 1996, the cumulative pregnancy risk was given for both correct and incorrect users of LAM as 0.88. This included all breastfeeding, sexually active women using LAM correctly or incorrectly (which means experiencing vaginal blood loss and not using any contraceptive method). The CPR for women using LAM correctly was even higher, being 0.97. In WHO 1999a, 13 pregnancies were reported in 2831 to 2969 WMAC, depending on which definition was used to mark the end of amenorrhoea. The cumulative life table pregnancy rate in fully breastfeeding, amenorrheic women not using any contraceptive method in that study was 0.9 to 1.2 (95% confidence interval 0 to 2.4).
Recurrence of 'menstruation' (vaginal blood loss) in uncontrolled studies
The above‐mentioned studies used the standard definition of LAM, that is ignoring any bleeding before the 56th day postpartum. Unfortunately, Kazi 1995 provided no data about the recurrence of menstruation. The number of menstruation recurrence/woman months of LAM use during the first 6 months were 40/432 (cumulative menstruation rate (CMR) 39.4) according to Ravera 1995 and 27/1179 (CMR 11.1) according to Cooney 1996. Ramos 1996 and Labbok 1997 did not provide these monthly data, giving only CMRs of 18.78 and 27.6, respectively. Only Díaz 1988a also presented data using the definition of any bleeding marking the end of amenorrhoea, reporting a life table menstruation rate after 6 months of using LAM of 135/937 (CMR 53.2). These data must be seen in the context that amenorrheic women were recruited 6 to 12 weeks after delivery. In the 1999 WHO study (WHO 1999a), the third definition of the end of amenorrhoea was used, that is a woman's perception that menstruation had resumed, but no menstruation life table rates were given.
In Rodríguez 1993, the women using LAM were fully breastfeeding and using an IUD. The CMR at 6 months was 32.
In the WHO study (WHO 1999a), the women in the intervention group were fully breastfeeding, and their CMR at 6 months varied from 26.5 to 69.5. Of note in this study was that 25.4% of these women experienced bleeding before the 56th day postpartum. In 44.4% (11.3/25.4) of them, this was separated by more than 14 days from the puerperal bleeding, and in 83.4% it was followed by a second bleed within 21 to 70 days. Egbuonu 2005 provided no cumulative rates or monthly life tables, reporting that menstrual flow returned in 33.8% of women by the sixth week of lactation and in 70.2% at six months.
Discussion
A systematic review of observational studies has many limitations owing to publication and language biases (Blettner 2000; Concato 2000; Sim 1996; Stroup 2000). In this review, we finally included 15 studies, reporting on 11 intervention and three control groups. The ways in which definitions were used, intervention and control groups composed, and data presented were not always clear. Even when they were clear, it did not make sense to pool these data, because we discovered that fertility and the length of amenorrhoea in fully breastfeeding women varied between different populations (Bonte 1974; Ford 1987; Ford 1993; Jones 1989; Kramer 2012; Lewis 1991; Radwan 2009; Sutton 2000; Valdés 2002; WHO 1999a). We observed serious heterogeneity among the women recruited. For example, Cooney studied the efficacy of LAM in Rwanda, where the national mean duration of breastfeeding was 25.9 months and lactational amenorrhoea 16.8 months before the introduction of LAM (Cooney 1996). In the study by Kazi, only women who had breastfed their previous child for at least one year were recruited (Kazi 1995). Realizing that pregnancy is the most important reason for weaning, it is likely that the women studied did not become pregnant during the first six months of their previous lactational amenorrhoea (Feinstein 1986; Jakobson 1996; Marandi 1993). The length of a previous amenorrhoea influences that of the next amenorrhoea, which will probably last longer. It may have been that the women studied would not likely become pregnant in the six months of using LAM during the study period (Delvoye 1977; Salber 1968; WHO 1999a).
Another weak point in the design of most of the included studies was the lack of a control group. A control group from the same culture/site is a prerequisite because the length of lactational amenorrhoea in fully breastfeeding women is culture and site specific (Kramer 2012; Trussell 1991a; WHO 1998a).
The LAM was introduced as a safe contraceptive method and a method to delay menstruation. Much effort and money was put into its promotion. However, in this review we found no differences in pregnancy rates between motivated and supported LAM users and women 'just' fully breastfeeding and staying amenorrheic. The suggestion that LAM delays the recurrence of menstruation more than does exclusive breastfeeding could not be supported.
Even after counseling, the percentage of women self reporting and evaluated as using LAM correctly is about 20% to 26% (Fabic 2013; Shaaban 2013; Sipsma 2013), and certain barriers (for example misconception about return of fertility) to LAM users' timely transition to regular contraceptive practice still exist (Kouyaté 2014).
Advocates of LAM have also suggested that its use would motivate women who have never used contraception before to use another contraceptive method after using LAM. Data supporting this idea gathered from a health centre may be biased. Owing to a lack of pregnancy tests, only women using LAM as a contraceptive method were allowed to have an IUD fitted without having a pregnancy test before insertion. Breastfeeding, amenorrheic women not using any contraceptive method did not receive an IUD because a pregnancy test could not be carried out before its insertion (Hardy 1998; Kennedy 1998a). LAM may even slow the transition to regular contraceptive practice, as suggested in the recent study of Shaaban (Shaaban 2013). In the LAM group, 45.2% of women started regular contraceptive practice in the six months after delivery compared to 73.4% in the LAM and emergency contraception group.
LAM has been promoted especially in low income countries, where it is difficult to obtain contraceptives. The results of Egbuonu 2005 are in this case alarming. In his study, LAM was not introduced as a contraceptive method; instead, exclusive breastfeeding for 178 women was promoted. No data on parity or on previous breastfeeding experience were given. Only 3.9% of these women were exclusively breastfeeding at 6 months, and 27.8% of the 144 women exclusively breastfeeding resumed sexual activity at 6 weeks after delivery. A return of menstrual flow occurred in 33.3% of the 144 exclusively breastfeeding women at 6 weeks and in 70.2% at 6 months for all breastfeeding women.
In Nigeria, where it is likely more difficult to obtain contraceptives compared with a high income country, it might be asked if the LAM method is applicable. In countries with a limited access to contraceptives, waiting for the end of the amenorrhoea before commencing another 'method' is not acceptable (Georgetown University 2008). A wiser course of action would be to use the first months after childbirth for the promotion of breastfeeding in the interest of the baby's health and to motivate the mother to use another contraceptive method, if required, and then arranging this (Bracher 1992; Hardy 1998; Hight‐Laukaran 1993; Kennedy 1991; Kennedy 1998a; Kunwar 2010; Labbok 1991; Potter 1973; Trussell 1991b).
| Trials | Entry point | Confounding of cases | Confounding of controls | Follow‐up length | Dropouts < 10% | Data clear | Endpoints clear | Same population |
| + | Unclear | + | Unclear | + | Unclear | ‐ | ||
| ‐ | Unclear | Unclear | + | + Cases | ‐ | + | ‐ | |
| + | ‐ | + | + | + | ‐ | + | ||
| + | ‐ | + | + | + | + | ‐ | ||
| + | ‐ | + | + | + | Unclear | ‐ | ||
| + | Unclear | Unclear | + | + Cases | ‐ | + | ‐ | |
| + | ‐ | + | + | + | + | ‐ | ||
| + | Unclear | + | Unclear | + | + | ‐ | ||
| ‐ | Unclear | + | + | ‐ | + | ‐ | ||
| + | ‐ | ‐ | + | + | ‐ | Unclear | + | |
| + | Unclear | + | Unclear | + | + | ‐ | ||
| LAM: lactational amenorrhoea method | ||||||||
