Combined oral contraceptive use among breastfeeding women: a systematic review

BackgroundPostpartum women need effective contraception, but using hormonal contraceptives may affect breastfeeding performance and infant health outcomes.Study designWe searched the MEDLINE and Cochrane databases for all articles published through May 2009 for primary research studies that investigated clinical outcomes among breastfeeding women who used hormonal contraception or their infants.ResultsThree randomized controlled trials reported decreased mean duration of breastfeeding and higher rates of supplemental feeding among combined oral contraceptive (COC) users than among nonusers, while one multicountry trial found no differences in these parameters. Only one study demonstrated lower average weights during the first year of life for infants whose mothers used COCs while breastfeeding. None of the eight studies, four of which were observational, included in this review documented adverse infant health outcomes.ConclusionsLimited evidence demonstrates an inconsistent effect of COC on breastfeeding duration and success. The evidence is inadequate to determine whether a mother's use of these drugs affects breastfeeding duration or the infant's health.