Early and Higher Volumes of Formula Supplementation after Birth Impact Breastfeeding Rates at Discharge in Well-Baby Nursery: A Retrospective Cohort Study

Abstract

Objective Physiologic breast milk production in the first 24 hours is estimated to be between 2 and 10 mL per feed. Many mothers intending to breastfeed use formula supplementation (FS) early on, which can affect successful breastfeeding. Whether the volume and timing of FS introduced in the first 24 hours of life (24 HOL) impacts the rate of “breastfeeding at discharge” (BFAD) is not well-studied and was investigated herein. Study Design Single-center, retrospective, chart review of breastfeeding infants born at ≥35 weeks who received supplementation in the first 24 HOL. Comprehensive demographic data pertaining to maternal and infant characteristics, along with infant feeding data, were collected. Four supplementation characteristics, (timing, rate, volume [mL/kg per feed], and type [expressed breast milk (EBM) or formula]) were correlated with BFAD. Results Among 3,102 supplemented infants in whom mothers intended to breastfeed, 1,031 (33.2%) infants were BFAD. At baseline, African American, Medicaid-insured, and single mothers had lower odds of BFAD. The overall maximum volume of FS per feed was 11.0 mL/kg (interquartile range 8.0–14.4). With each hour of delay in first supplementation, the odds of BFAD increased by 2.8% (95% confidence interval [CI] 0.022, 0.035). With every 1 mL/kg increase in the first formula volume, subsequent supplementation frequency increased by 4.5%. A positive association was observed between BFAD and a lower rate of supplementation (cutoff value ≤35.1%). However, among infants with these lower rates of supplementation, each unit increase in maximum FS, from 2 to 15 mL/kg, decreased the probability of BFAD by 4.2% (3.6–4.7%). Additionally, we observed that infants who were given at least one EBM supplementation (n = 223; 7.2%) had substantially increased rates of BFAD (odds ratio [OR] = 9.8, 95% CI 7.2–13.3). Conclusion Early and higher volumes of FS negatively impacted BFAD. Birthweight-based FS of feeding with physiological volumes may increase breastfeeding rates at discharge. Key Points