National Breastfeeding Month

The Lactational Amenorrhea Method: Effectiveness Data Combats Myths

By: Jefferson Adams, DO

Director’s Note: To mark the beginning of National Breastfeeding Month, we are highlighting research on the Lactational Amenorrhea Method (LAM). While you can learn more about LAM and other fertility awareness-based methods (FABMs) through the FACTS elective and our CME course, there is a need for continued research across methods, especially LAM. A former student on the FACTS elective, Dr. Jefferson Adams summarizes a research study published in 1997 about the efficacy, duration, and clinical applications of LAM.[1]  Yet, more studies have been conducted in the last thirty years, including a 2022 study on lactational amenorrhea published in the International Journal of Molecular Sciences.[2] Whether you are a student, clinician or educator, if you are interested in learning more about LAM, join us for our Revitalizing Women’s Health conference this September 29-30 in Minneapolis, MN to hear from Gregory Plotnikoff, MD about the role of vitamins A and D in pregnancy and breastfeeding.

Introduction

Prior studies have shown the lactational amenorrhea method (LAM) has an efficacy as high as 99.55% with correct use at six months.[3] Nevertheless, lactational amenorrhea remains an underutilized option for couples trying to avoid pregnancy in the postpartum period.[1] It is thought this is primarily due to misconceptions claiming low efficacy[1] and that LAM is an “old wives’ tale.” The study[1] by Labbok et al summarized below followed 519 women and was designed to demonstrate the realistic clinical effectiveness of LAM in a diverse set of populations, cultures, and health care settings.

Three criteria have been established for the correct use of LAM that, while relatively simple, may reduce efficacy if a couple is unaware or does not adhere to the criteria appropriately. The criteria are as follows: [1,3]

(1) Menses has not yet returned.
(2) The infant is breastfed exclusively without any supplementation and feeds are done regularly, including at night, and
(3) The infant must be less than six months old.

Methodology

In this study, various terms were defined to maintain consistency throughout the eleven sites. ‘Return of menses’ was indicated by three days of spotting in a row, two days of spotting and one day of bleeding, or two days in a row of the woman’s typical bleeding.[1] The following parameters were used to define the ‘exclusively or near-exclusively breastfed’ component of the criteria:

• Following milk let-down, the feeding session must continue for at least 4 minutes. For a woman to be considered fully breastfeeding, she must nurse her child 6 to 10 times per 24 hours depending on the length of the feeding — 6 times for long feeds or 10 times for short feeds.
• Supplementation with other food sources, including stored, previously expressed milk, is limited as follows: 1 ounce/wk at 1 month old, 2 ounces/wk at 2 months old, and 3 ounces/wk at 3 months old. LAM was considered to be discontinued with more than a 10-hr gap between feeds or a 6-hr gap between feedings at least twice in a given week.
• Although LAM was considered discontinued at 6 months postpartum, some women chose to continue using LAM past the 6-month mark if menses had not returned.[1] Their data was recorded as well. As part of the original study protocol, each patient had monthly follow-up visits prior to six months and then additional visits at nine and twelve months.[1]

“For a woman to be considered fully breastfeeding, she must nurse her child 6 to 10 times per 24 hours depending on the length of the feeding — 6 times for long feeds or 10 times for short feeds.”

Results

This study found that for the 2,718 woman-months that were studied, LAM had an average “correct-use” efficacy of 98.5% (low: 92.5%, high: 100%) at six months, with an “incorrect-use” efficacy of 98.3% at six months.[1] At twelve months of use, the remaining 71 women who had not switched to another form of contraception and who were still amenorrheic had a LAM efficacy of 92.2%.[1] This number included the data from “correct” and “incorrect” use, so the authors identified this 92.2% at twelve months as the “typical” use effectiveness for LAM.[1]

The study also found a 72.4% probability of not having a return to normal menses by six months post-partum, with a likelihood of 42.1% at thirteen months.[1] The frequency of intercourse per couple during this six-month period was also reported: across all countries studied, the average increased steadily to 4.9 times per month by the sixth month.[1]

Discussion

Inclusion of 2,718 women months for the six-month period studied provides adequate power for the results. The inclusion of ten countries delivered significant diversity in terms of education, resources, wealth, health clinics, and cultural differences. With these two factors in mind, this study appears to be generalizable to a broad population. Additionally, since LAM is only designed for the six months postpartum, it can be difficult to compare it directly with other forms of family planning or contraceptives.[1] Still, the 98.5% efficacy at six months and 92.2% efficacy at twelve months without the addition of a second contraceptive method is strong evidence that LAM works effectively.

“The 98.5% efficacy at six months and 92.2% efficacy at twelve months without the addition of a second contraceptive method is strong evidence that LAM works effectively.”

One of the barriers to LAM’s general acceptance and widespread use in clinical practice is likely its unfortunate status as an “old-wives’ tale.” The technical parameters for the method’s effectiveness likely hinder its use as well. The high efficacy of LAM, as reported in this study, requires regular breastfeeding with no more than 6 hours between any two feeds, including through the night. This is a challenge for many couples and places a higher burden on the woman who has to get up and nurse at regular intervals. If a couple is unfamiliar with this requirement or their medical professional is unaware and/or does not educate them properly, the couple is unlikely to meet the required criteria for “correct-use” of LAM and will experience a lower efficacy. This potential knowledge gap is a likely source of the belief that LAM is an ineffective method of family planning in the postpartum period.

Nevertheless, the “incorrect-use” efficacy was 98.3%, suggesting strict adherence to the three criteria for LAM is unnecessary. Yet, the degree to which couples used the method “incorrectly” is not defined beyond a change in “one of the parameters [of the 3 criteria] but before the introduction of another family planning method.”[1] It would be helpful to explore further how duration between feedings during the day or overnight affects LAM’s efficacy. For example, two instances of seven-hour gaps in feedings within a given week may not change the efficacy of LAM significantly, but this woman would fall under the “incorrect use” percentage based on the study parameters. Delineating to what degree feeding intervals can vary while maintaining a similar efficacy could help alleviate some of the perceived burden or stress on a couple when considering a postpartum family planning method.

“LAM is a highly effective form of family planning in the postpartum timeframe … (that) promotes good child spacing and healthy breastfeeding behaviors which are beneficial for both mother and infant.”

Conclusion  

LAM is a highly effective form of family planning in the postpartum timeframe. This was found to be true across multiple continents and in a wide diversity of cultures.[1] The method promotes good child spacing and healthy breastfeeding behaviors which are beneficial for both mother and infant.[1] LAM is an inexpensive, very accessible option for women and couples in a variety of settings. Further promotion of the real data behind LAM, including data reported after this study, is necessary to help women make a more informed decision about their postpartum family planning options.

Sources

[1] Labbok MH, Hight-Laukaran V, Peterson AE, Fletcher V, von Hertzen H, Van Look PF. Multicenter study of the Lactational Amenorrhea Method (LAM): I. Efficacy, duration, and implications for clinical application. Contraception. 1997;55(6):327-336. doi:10.1016/s0010-7824(97)00040-1.
[2]Calik-Ksepka A, Stradczuk M, Czarnecka K, Grymowicz M, Smolarczyk R. Lactational Amenorrhea: Neuroendocrine Pathways Controlling Fertility and Bone Turnover. Int J Mol Sci. 2022;23(3):1633. Published 2022 Jan 31. doi:10.3390/ijms23031633
[3] Labbok MH, Perez A, Valdes V, et al. The Lactational Amenorrhea Method (LAM): a postpartum introductory family planning method with policy and program implications. Adv Contracept. 1994;10(2):93-109. doi:10.1007/BF01978103.

ABOUT THE AUTHOR

Jefferson Adams

Jefferson Adams, DO is in his intern year of family medicine residency at UPMC Altoona Family Physicians in Pennsylvania. He graduated from the Kentucky College of Osteopathic Medicine in Pikeville, KY. He has a strong interest in holistic care including the use of osteopathic manipulative treatment in clinical practice. Dr. Adams took part in the FACTS elective during medical school to gain a deeper understanding of women’s reproductive health and to learn more about fertility awareness-based methods of family planning. He plans to incorporate these methods into his practice to provide women more options for their family planning and reproductive healthcare.