Feeding preterm infants after hospital discharge: Growth and development at 18 months of age

We have shown that preterm infants fed a preterm formula grow better than t hose fed a standard term infant formula after hospital discharge. The purpo se of this follow-up study was to determine whether improved early growth w as associated with later growth and development. Preterm infants (less than or equal to 1750 g birth weight, less than or equal to 34 wk gestation) we re randomized to be fed either a preterm infant formula (discharge to 6 mo corrected age), or a term formula (discharge to 6 mo), or the preterm (disc harge to term) and the term formula (term to 6 mo). Anthropometry was perfo rmed at 12 wk and 6, 12, and 18 mo. Mental and psychomotor development were assessed using the Bayley Scales of Infant Development II at 18 mo. Differ ences in growth observed at 12 wk were maintained at 18 mo. At 18 mo, boys fed the preterm formula were 1.0 kg heavier, 2 cm longer, and had a 1.0 cm greater occipitofrontal circumference than boys fed the term formula. Boys fed the preterm formula were also 600 g heavier and 2 cm longer than girls fed the preterm formula. However, no differences were noted in MDI or PDI b etween boys fed the preterm formula and boys fed the term formula or betwee n the boys fed preterm formula and girls fed the preterm formula. Overall, boys had significantly lower MDI than girls (mean difference, 6.0; p < 0.01 ), primarily reflecting lower scores in boys fed the term formula. Thus, ea rly diet has long-term effects on growth but not development at 18 mo of ag e. Sex remains an important confounding variable when assessing growth and developmental outcome in these high-risk infants.