Effects of human milk or formula feeding on the growth, behavior, and protein status of preterm infants discharged from the newborn intensive care unit.

The growth, behavior, and protein status of 59 healthy preterm (mean gestational age 30 wk) infants fed either human milk or one of three infant formulas were studied post-discharge from the hospital. Formula-fed infants received either a standard term formula, a standard preterm formula, or an experimental preterm formula from discharge to 8 wk of age. From 8 to 16 wk, all formula-fed infants received the standard term formula. At 2, 8, and 16 wk, anthropometric, dietary intake, blood biochemistry, amino acid, and Brazelton Neonatal Behavioral Assessment measurements were evaluated. Weights, lengths, and head circumferences were similar for all feeding groups at discharge. After discharge all formula-fed infants were heavier than human milk-fed infants. Length and head circumference values and plasma urea nitrogen and retinol-binding protein concentrations were not different among dietary groups. Formula-fed infants had higher plasma concentrations of numerous amino acids compared with those of human milk-fed infants during the first 8 wk but not at 16 wk. There were no differences among the feeding groups in the Brazelton assessment. This study found little effect on the growth or behavioral or protein status of preterm infants discharged from the hospital who were fed either human milk or formulas designed for term or preterm infants.