title: Progestogen-only contraceptive use among breastfeeding women: a systematic review.
abstract: BACKGROUND
  The use of progestogen-only contraceptives by breastfeeding women raises theoretical concerns regarding possible adverse effects on breastfeeding success, and infant health or growth. This review was conducted to determine from the literature whether use of progestogen-only contraceptives by breastfeeding women leads to adverse effects on lactation, or infant growth or health when compared to nonuse.
  
  
  METHODS
  We searched the Medline, Popline, Cochrane and LILACS databases for all articles published from database inception through May 2009. Studies were included if they investigated the use of progestogen-only methods in breastfeeding women and reported on clinical outcomes in either women or their infants. Standard data abstraction templates were used to systematically assess and summarize. Summary odds ratios were not calculated, given the heterogeneity of interventions, results and non-quantifiable outcomes reported.
  
  
  RESULTS
  We identified 43 articles for this review. Overall, five randomized trials and 38 observational studies demonstrated no adverse effects of various progestogen-only methods of contraception on multiple measures of breastfeeding performance through 12 months in women using these methods in the postpartum period. Many of these studies also demonstrated no adverse effects of progestogen-only methods on infant growth, health or development from 6 months to 6 years of age. Additional studies demonstrated no effects on infant immunoglobulins or sex hormones of exposed male infants. A single study of a desogestrel pill reported two cases of gynecomastia in exposed infants.
  
  
  CONCLUSIONS
  Evidence suggests that progestogen-only methods of contraception do not adversely affect breastfeeding performance when used during lactation. Evidence that progestogen-only contraception does not adversely affect infant growth, health, or development when used by breastfeeding women is consistent but methodologically limited.
authors.affiliation: Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland. kappn@who.int
authors.forename: Nathalie
authors.initials: N
authors.lastname: Kapp
authors.forename: Kathryn
authors.initials: K
authors.lastname: Curtis
authors.forename: Kavita
authors.initials: K
authors.lastname: Nanda
mesh_terms: D000328:Adult; D001942:Breast Feeding; D002648:Child; D002657:Child Development / Q000187:drug effects; D002675:Child, Preschool; D003271:Contraceptive Agents, Female / Q000008:administration & dosage / Q000009:adverse effects*; D017135:Desogestrel / Q000009:adverse effects; D005260:Female; D006128:Growth / Q000187:drug effects; D006801:Humans; D007223:Infant; D007774:Lactation / Q000187:drug effects; D016239:MEDLINE; D008297:Male; D011372:Progestins / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D003271:Contraceptive Agents, Female; D011372:Progestins; D017135:Desogestrel