Postpartum Contraceptive Implants and Breast-Feeding: Reassuring Results

Although subdermal contraceptive implants are more effective than tubal ligation, they are less commonly chosen by postpartum women. To assess the effect on milk production of subdermal contraception placed within 48 hours of delivery, Brazilian researchers randomized 24 mothers who had previously breast-fed to subdermal implants or no hormonal contraception for the first 6 weeks after delivery. All participating mothers ingested 5 grams of “heavy water” (deuterium oxide, D₂O) within 48 hours of delivery and another 10 grams of D₂O 1 month later. Infant salivary D₂O levels were measured to determine the amount of milk infants ingested on days 1, 2, 3, 4, 13, and 14 after maternal D₂O ingestion. In addition, participants completed questionna…