Objective: Extremely preterm infants are at risk for poor growth and impaired neurodevelopment. The objective of this study was to determine whether intrauterine, early neonatal, or postdischarge growth is associated with neurocognitive and motor-developmental outcome in extremely preterm infants.

Methods: Surviving children who were born between July 1996 and June 1999 at <30 weeks' gestation and with a birth weight <1500 g were evaluated at the age of school entry by application of (1) a standardized neurologic evaluation, (2) the Kaufmann Assessment Battery for Children, and (3) the Gross Motor Function Classification Scale. Growth was assessed on the basis of SD scores of weight and head circumference measured at birth, at discharge, and at the time of the follow-up examination. All infants had received intensive early nutritional support.

Results: A total of 219 (83%) of 263 long-term survivors were evaluated at a median corrected age of 5.4 years. Increasing SD scores for weight and head circumference from birth to discharge were associated with a reduced risk for an abnormal neurologic examination. Catch-up growth of head circumference from birth to discharge was also associated with a reduced risk for impaired mobility. Weight SD score at birth, an increase of weight SD score from birth to discharge, and an increase of head circumference SD score from discharge to follow-up had an effect on the mental processing composite score. The effects of growth on neurodevelopment were by far exceeded by the consequences of intraventricular and periventricular hemorrhage.

Conclusions: Growth from birth to discharge seemed to be associated with long-term motor development. Cognitive development was associated with intrauterine growth measured as weight at birth, early neonatal weight gain, and postdischarge head circumference growth. Improving particularly early neonatal growth may improve long-term outcome in extremely preterm infants, but the effects of improved growth may only be small.