Background: Contraception is important for women who are postpartum, including those who are breastfeeding. Use of combined hormonal contraceptives (CHCs) may affect breastfeeding performance and infant health outcomes.
Objective: The objective was to identify evidence examining clinical outcomes for breastfeeding and infant health among breastfeeding women using CHCs compared to nonusers.
Search strategy: We searched the PubMed database for all articles published from database inception through September 30, 2014.
Selection criteria: We included primary research studies that compared breastfeeding women using CHCs with breastfeeding women using nonhormonal or no contraception, or compared breastfeeding women initiating combined hormonal contraception at early versus later times postpartum. Breastfeeding outcomes of interest included duration, rate of exclusive breastfeeding and timing of supplementation. Infant outcomes of interest included growth, health and development.
Results: Fifteen articles describing 13 studies met inclusion criteria for this review. Studies ranged from poor to fair methodological quality and demonstrated inconsistent effects of combined oral contraceptives (COCs) on breastfeeding performance with COC initiation before or after 6 weeks postpartum; some studies demonstrated greater supplementation and decreased breastfeeding continuation among COC users compared with nonusers, and others demonstrated no effect. For infant outcomes, some studies found decreases in infant weight gain for COC users compared with nonusers when COCs were initiated at <6 weeks postpartum, while other studies found no effect. None of the studies found an effect on infant weight gain when COCs were started after 6 weeks postpartum, and no studies found an effect on other infant health outcomes regardless of time of COC initiation.
Conclusion: Limited evidence of poor to fair quality demonstrates an inconsistent impact of COCs on breastfeeding duration and success. The evidence also demonstrated conflicting results on whether early initiation of COCs affects infant outcomes but generally found no negative impact on infant outcomes with later initiation of COCs. The body of evidence is limited by older studies using different formulations and doses of estrogen and poor methodologic quality. Given the significant limitations of this body of evidence, the importance of contraception for postpartum women and the theoretical concerns that have been raised about the use of combined hormonal contraception by women who are breastfeeding, rigorous studies examining these issues are needed. In addition, postpartum women should be counseled about the full range of safe alternative contraceptive methods, particularly during the first 6 weeks postpartum when the risk of venous thromboembolism is highest and use of estrogen may exacerbate this risk.
Keywords: Breastfeeding; Combined hormonal contraceptives; Combined oral contraceptives; Lactation; Systematic review.
Copyright © 2016. Published by Elsevier Inc.