In-hospital formula use increases early breastfeeding cessation among first-time mothers intending to exclusively breastfeed.

Objective To evaluate in-hospital formula supplementation among first-time mothers who intended to exclusively breastfeed and determined if in-hospital formula supplementation shortens breastfeeding duration after adjusting for breastfeeding intention. Study design We assessed strength of breastfeeding intentions prenatally in a diverse cohort of expectant primiparae and followed infant feeding practices through day 60. Among mothers planning to exclusively breastfeed their healthy term infants for ≥1 week, we determined predictors, reasons, and characteristics of in-hospital formula supplementation, and calculated the intention-adjusted relative risk (ARR) of not fully breastfeeding days 30-60 and breastfeeding cessation by day 60 with in-hospital formula supplementation (n = 393). Results Two hundred ten (53%) infants were exclusively breastfed during the maternity stay and 183 (47%) received in-hospital formula supplementation. The most prevalent reasons mothers cited for in-hospital formula supplementation were: perceived insufficient milk supply (18%), signs of inadequate intake (16%), and poor latch or breastfeeding (14%). Prevalence of not fully breastfeeding days 30-60 was 67.8% vs 36.7%, ARR 1.8 (95% CI, 1.4-2.3), in-hospital formula supplementation vs exclusively breastfed groups, respectively, and breastfeeding cessation by day 60 was 32.8% vs 10.5%, ARR 2.7 (95% CI, 1.7-4.5). Odds of both adverse outcomes increased with more in-hospital formula supplementation feeds (not fully breastfeeding days 30-60, P  = .003 and breastfeeding cessation, P  = .011). Conclusions Among women intending to exclusively breastfeed, in-hospital formula supplementation was associated with a nearly 2-fold greater risk of not fully breastfeeding days 30-60 and a nearly 3-fold risk of breastfeeding cessation by day 60, even after adjusting for strength of breastfeeding intentions. Strategies should be sought to avoid unnecessary in-hospital formula supplementation and to support breastfeeding when in-hospital formula supplementation is unavoidable.