Association Between Infant Feeding Modes and Gastroesophageal Reflux: A Repeated Measurement Analysis of the Infant Feeding Practices Study II

Abstract

Background: Gastroesophageal reflux in neonates is frequently reported by parents, potentially motivating changes in infant feeding mode and/or addition of solid food. Objective: The authors prospectively analyzed associations between repeated measurement of feeding modes and reflux in infancy. Methods: The Infant Feeding Practices Study II, conducted between 2005 and 2007 (2,841 infants), provides data on reflux and feeding modes at nine time points from months 1 to 12. Feeding modes were defined based on direct breastfeeding, feeding of bottled human milk, formula feeding, their combinations, and use of solid food. Repeated measurements were investigated using 1-month delayed models to estimate risk ratios (RRs) and their 95% confidence intervals (CIs). Risk ratios of different feeding modes were estimated for reflux; addressing a reverse association, RRs for feeding mode were estimated as responses to prior reflux. Results: Compared to direct breastfeeding, combinations with formula feeding showed a statistically significant risk for reflux (bottled human milk plus formula feeding: RR = 2.19, 95% CI [1.11, 4.33]; formula feeding: RR = 1.95, 95% CI [1.39, 2.74]; and mixed breastfeeding plus formula feeding: RR = 1.59, 95% CI [1.40, 2.42]). Addition of solid food was not protective (RR = 1.21, 95% CI [0.86, 1.70]). Analyses of reverse association (reflux → feeding) showed fewer breastfed infants among those with reflux in the prior month. Conclusion: Any combination of infant feeding with formula seems to be a risk for reflux. Although breastfeeding was protective, mothers with a child with reflux were more likely to wean their child.