When it comes to postpartum contraception methods, many people consider condoms or birth control pills, but there’s another option that’s more effective than either of those: the lactational amenorrhea method (LAM), which is at least 98% effective. 

A new UC Davis Health study published in Breastfeeding Medicine found that many women in the U.S. are misinformed about or lack understanding of lactational amenorrhea. It’s the period of temporary infertility that accompanies exclusive breastfeeding, which is marked by the absence of monthly periods. The study concluded that nearly half of women surveyed by the researchers were unaware that exclusive breastfeeding would significantly reduce their risk of pregnancy until their monthly periods resumed. 

“This study is important as there is very limited information regarding use of lactational amenorrhea as a planned contraceptive in pregnant women here in the United States,” said Adrienne Hoyt-Austin, first author of the study. “Comprehensive education about postpartum contraceptive options is important to prevent unplanned pregnancies. To improve awareness of LAM, pregnant and postpartum individuals should be counseled on all forms of postpartum contraception, including LAM.” 

An estimated 1.5 million women worldwide use LAM inappropriately, potentially leading to unplanned pregnancy. 

Misinformation surrounding LAM as contraception 

The study screened 760 U.S.-born pregnant women who had never given birth. They were recruited through advertisements on Facebook and Instagram, which led to a screening questionnaire and then enrollment. The study focused on women who:

• Had never given birth
• Were 27–37 weeks pregnant with only one child
• Were 18-40 years old
• Could read English
• Had reliable access to a telephone for texting, and internet access. 

Participants were given a $20 gift card for completing the survey. 

Of 760 individuals screened, 627 were invited to participate and 451 (72%) were enrolled. Participants completed surveys on sociodemographic information, infant feeding plans and postpartum contraceptive methods. They were asked about their perceptions of the effectiveness of certain postpartum contraceptives. Participants were also asked about their understanding of LAM criteria (for example, “True or false: Breastfeeding will delay my menstrual period after birth.”) 

Among the survey’s findings: 

• About half of respondents were aware that breastfeeding can delay the return of their monthly periods. However only 11.3% understood that exclusive breastfeeding is necessary to rely on LAM and many (47.3%) didn’t know that exclusive breastfeeding is needed to reduce pregnancy risk.
• More than a quarter (28%) knew that LAM is only effective until their monthly periods return. Another 42% indicated LAM was “a little” and 8.4% indicated “a lot” effective to protect against pregnancy in the first six months postpartum.
• Most participants believed that condoms (87.3%) were more effective than LAM. Participants also believed that birth control pills (87.8%) were more effective than LAM.
• Of those participants considering LAM for their contraception, 60% were not aware that exclusive breastfeeding is a requirement of LAM. 

“Although LAM has been demonstrated to be an effective contraception in exclusively breastfeeding individuals for the first six months postpartum, few participants were aware that LAM is more effective than typical use of birth control pills or condoms,” Hoyt-Austin said. “This is unfortunate, as breastfeeding has multiple long-term benefits for the health of both women and children.” 

The study concludes that new parents may benefit from comprehensive counseling about postpartum contraception that includes information about LAM. For those planning to rely on breastfeeding as a method of contraception, the essential components of LAM should be carefully and clearly explained. 

Other study authors include Melissa Chen, Susan Brown, Margaret Fix and Laura Kair, of UC Davis Health; Caidon Iwuagwu, of UC Davis; and Eleanor Schwarz, of UC San Francisco. 

This research was supported by the HRSA (R40MC35364), National Institutes of Health (NOSI supplement to K23HD101550), the National Center for Advancing Translational Sciences, National Institutes of Health (UL1 TR001860), Building Interdisciplinary Research Careers in Women's Health, National Institutes of Health (K12 HD051958) and the HEAL-HER Program funded by a Wyeth Settlement award to UC Davis.