Nutrient-enriched Infant Formula Is Associated With Higher Weight Gain for Low Birth Weight Infants

Nutrient-enriched formulas were developed to provide extra nutrients and facilitate optimal growth for low birth weight infants. This study examined the association between use of nutrient-enriched formulas and weight gain among low birth weight infants (birth weight 1500–2500 g). This retrospective cohort study used data from infants enrolled in the Illinois Special Supplemental Nutrition Program for Women, Infants, and Children. Analyses were limited to infants born in 2010 with low birth weight (1500–2500 g, n = 3130). We examined weight gain by use of nutrient-enriched versus standard term formula, which was assigned to the infant by the Women, Infants, and Children program during the first month of life. The analyses used a multilevel mixed-effects linear regression model with random intercepts to determine the association between use of enriched versus standard term formula and weight gain while simultaneously adjusting for confounders including gestational age, birth weight, and history of breast-feeding. Among 670 infants in the 1500 to 1999 g birth weight group, those fed enriched formula gained 46.4 g (95% confidence interval 7.4–85.3, P< 0.05) more per month in the first 6 months, and 34.0 g (95% confidence interval -0.4 to 68.3, P= 0.05) more per month >6 to 12 months of age compared with infants using standard term infant formula after adjustment for covariates. Similar findings were noted among the 2460 infants in the 2000 to 2500 g birth weight group. Use of nutrient-enriched formulas is associated with higher weight gain in low birth weight infants.