Effect of Breastmilk Consumption on Neurodevelopmental Outcomes at 6 and 12 Months of Age in VLBW Infants

Purpose: To determine the influence of breastmilk consumption, as a dose response, in very low-birth-weight (VLBW) infants (< 1,500 g) on neurodevelopmental outcomes at 6 and 12 months corrected age, and to determine the influence of selected sociodemographic and infant variables on neurodevelopmental outcomes.

Subjects: VLBW infants (n = 148) who were fed mother's milk or formula by parental choice.

Design: Prospective cohort with longitudinal follow-up at 6 and 12 months corrected age.

Methods: Self-administered questionnaires given to mothers at study entry, before discharge, and at 3-, 6-, and 12-month follow-up visits. During hospitalization, mothers recorded the 24-hour volume of expressed milk once per week. At each follow-up visit, the volume of a single feeding was assessed by pre- and postbreastfeeding test weights of infants measured on an electronic scale accurate to 1.0 g. The amount of breastfeeding was also assessed by feeding records and mother's report.

Main Outcome Measures: The Bayley Scales of Infant Development (2nd Edition), the Mental Developmental Index (MDI), and the Psychomotor Developmental Index (PDI).

Principal Results: After controlling for specific sociodemographic and infant variables, this study of VLBW infants showed no statistically significant effect of predominantly breastfeeding compared with predominantly formula feeding on neurodevelopmental outcomes to 12 months corrected age. The most significant predictor of MDI scores at 6 and 12 months corrected age was birth weight, in which higher birth weights predicted higher MDI scores.

Conclusions: Despite the lack of statistically significant differences, the findings suggest a small but consistent advantage in developmental scores in infants who were fed their mother's milk compared with those who were predominantly formula fed. Supporting parents to breastfeed preterm infants may maximize the potential advantages of early nutrition in the neurodevelopmental outcome of VLBW infants.