Breastfeeding Outcomes Associated With the Special Supplemental Nutrition Program for Women, Infants, and Children: A Systematic Review.

Background: The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) promotes and supports breastfeeding for low-income women and children. A prior review reported negative associations of WIC with breastfeeding outcomes. WIC food package changes in 2009 increased breastfeeding support.

Objective: The objectives of this systematic review were to 1) evaluate evidence on WIC participation and breastfeeding outcomes and 2) evaluate breastfeeding outcomes of WIC participants before versus after the 2009 food package.

Data Sources: PubMed, Embase®, CINAHL, ERIC, SCOPUS, PsycINFO, and the Cochrane Central Register of Controlled Trials for papers published January 2009 to April 2022.

Eligibility Criteria: Included studies compared breastfeeding outcomes (initiation, duration, exclusivity, early introduction of solid foods) of WIC participants with WIC-eligible nonparticipants, or among WIC participants before versus after the 2009 package change.

Study Appraisal Methods: Two independent reviewers evaluated each study and assessed risk of bias using EHPHP assessment.

Results: From 13 observational studies we found: 1) moderate strength of evidence (SOE) of no difference in initiation associated with WIC participation; 2) insufficient evidence regarding WIC participation and breastfeeding duration or exclusivity; 3) low SOE that the 2009 food package change is associated with greater breastfeeding exclusivity; 4) low SOE that WIC breastfeeding support services are positively associated with initiation and duration.

Limitations: Only observational studies, with substantial risk of bias and heterogeneity in outcomes and exposures.

Conclusions And Implications Of Key Findings: WIC participation is not associated with a difference in breastfeeding initiation compared to WIC-eligible nonparticipants, but the 2009 food package change may have improved breastfeeding exclusivity among WIC participants and receipt of breastfeeding support services may have improved breastfeeding initiation and duration.