From the Guidelines
Lactational amenorrhea (LA) is not specifically effective for maintaining a healthy endometrial lining or supporting fertility, but rather functions as a temporary natural contraceptive method. During exclusive breastfeeding, prolactin levels remain elevated, which suppresses ovulation and results in the absence of menstruation, as noted in the U.S. Medical Eligibility Criteria for Contraceptive Use, 2010 1. This state does not actively promote endometrial health or enhance fertility—in fact, it temporarily suppresses fertility by design. Once breastfeeding decreases, especially after introducing solid foods or when the baby sleeps through the night, prolactin levels drop, allowing ovulation to resume and the endometrium to return to its normal cycle.
The effectiveness of LA as contraception is highest (98%) during the first six months postpartum when breastfeeding is exclusive, the mother remains amenorrheic, and the infant is less than six months old, as supported by the U.S. Selected Practice Recommendations for Contraceptive Use, 2013 1. After this period, additional contraception should be considered if pregnancy prevention is desired, as fertility may return before the first postpartum menstruation. It's also important to note that LA does not protect against sexually transmitted infections (STIs) and human immunodeficiency virus (HIV), and the correct and consistent use of condoms is recommended if risk exists, as stated in the U.S. Medical Eligibility Criteria for Contraceptive Use, 2010 1.
Some key points to consider:
- LA is a temporary natural contraceptive method that suppresses ovulation and menstruation during exclusive breastfeeding.
- The effectiveness of LA as contraception is highest during the first six months postpartum when breastfeeding is exclusive, the mother remains amenorrheic, and the infant is less than six months old.
- LA does not protect against STIs and HIV, and the correct and consistent use of condoms is recommended if risk exists.
- For women concerned about endometrial health or fertility, LA should not be relied upon as a treatment, and additional methods should be considered, as suggested by the ACOG committee 1.
From the Research
Lactational Amenorrhea and Fertility
- Lactational amenorrhea (LA) is a state of temporary infertility that occurs in breastfeeding women, characterized by the absence of menstruation 2, 3, 4, 5, 6.
- The lactational amenorrhea method (LAM) is a contraceptive method that utilizes LA to prevent pregnancy, and is considered effective for up to six months postpartum, provided the mother is exclusively breastfeeding and has not resumed menstruation 2, 3, 4.
- Studies have shown that LAM is at least 98% effective in preventing pregnancy, comparable to other contraceptive methods 2.
- However, the effectiveness of LAM in maintaining a healthy endometrial lining and supporting fertility is not well established, with some studies suggesting that LA may have a suppressive effect on the hypothalamic-pituitary-ovarian axis, leading to anovulation and amenorrhea 6.
Mechanisms of Lactational Amenorrhea
- Suckling is the primary stimulus that maintains the suppressive effect on the ovaries during lactation, leading to high levels of prolactin and suppression of gonadotropin-releasing hormone (GnRH) secretion 6.
- The suppression of GnRH secretion results in decreased luteinizing hormone (LH) pulses, leading to anovulation and amenorrhea 6.
- The lactational amenorrhea method is based on the fulfillment of three simultaneous conditions: the baby is under 6 months, the mother is still amenorrheic, and she practices exclusive or quasi-exclusive breastfeeding on demand, day and night 2.
Implications for Fertility
- Lactational amenorrhea may have implications for fertility, as it can delay the return of menstruation and ovulation 2, 3, 4, 5, 6.
- However, the impact of LA on fertility is not well understood, and more studies are needed to determine the effects of behavioral factors, such as suckling parameters, on LAM efficacy 6.
- Clinicians should provide counseling on LAM as a contraceptive option, including its effectiveness, benefits, and limitations, to support informed decision-making among breastfeeding women 5.