Brainstem maturation in premature infants as a function of enteral feeding type

Objective. To determine whether brainstem maturation as measured by brainstem auditory-evoked responses (BAERs) in preterm infants is a function of dietary intake. Study Design. We obtained serial BAERs on infants 28 to 32 weeks' gestation at birth, cared for in the neonatal intensive care unit of a regional referral center in Upstate New York. Waveforms were analyzed for replicability and for the presence of waves III and V. Absolute and interwave latencies were measured. Baseline and follow-up BAER measurements were compared, and the rates of change were calculated. Patient charts were reviewed for type of enteral feeding during the interval between BAERs. Student's t test was used to analyze continuous variables and chi(2) analysis was used to analyze categorical variables. Results. Data from 37 study infants (17 fed breast milk and 20 fed commercial premature formula) revealed that there was no difference in absolute latencies of waves III and V at baseline; however, the rates of decrease of absolute latencies over the study interval were significantly greater in infants receiving human milk. Conclusions. Infants fed breast milk have faster brainstem maturation, compared with infants fed formula, based on the rate of maturation of BAERs. This effect may be attributable to the constituent composition of breast milk, compared with synthetic formulas.