AbstractContextLactation causes a delay in ovulation in the postpartum period, and therefore a delay in the resumption of menses. However, return to fertility is variable in the postpartum period and is contingent upon numerous factors. The postpartum period is therefore a critical time to initiate effective contraception in order to support the numerous beneficial health outcomes of optimal pregnancy spacing. Breastfeeding women have an unmet need for highly effective birth control methods that do not interfere with lactation and that are safe for their infants. The progesterone-releasing vaginal ring (PVR) releases a natural progesterone that suppresses ovulation and is specifically designed for breastfeeding women in the first postpartum...