Fertility After Childbirth: Lactational Amenorrhea and Return of Ovulation

Exclusive, frequent breastfeeding (every 4–6 hours day and night) suppresses ovulation via elevated prolactin, providing ~98% contraceptive efficacy for the first 6 months postpartum if menses have not returned. However:

• Ovulation precedes first menses—pregnancy can occur before a period.
• Partial breastfeeding, formula supplementation, or solid foods reduce protection.
• Non-breastfeeding women may ovulate as early as 3–4 weeks postpartum.

If another pregnancy is not desired, discuss contraception (progestin-only pill, IUD, implant, barrier) with your clinician at the postpartum visit. Do not rely on breastfeeding alone unless all LAM criteria are met.