The impact of intrauterine growth restriction (IUGR) in very low birthweight preterm infants weighing < or = 1250 g was determined by comparing longitudinal growth and neurodevelopmental outcome to an adjusted age of 36 months in 52 intrauterine growth restricted children, with 55 birthweight-matched and 56 gestational age-matched children. None of these children had chromosomal anomalies, congenital infections, or major congenital malformations. Gestational ages of intrauterine growth restricted, birthweight- and gestational age-matched infants were 30 (+/-3), 26 (+/-2), 29 (+/-2) weeks: birthweights were 842 (+/-232), 872 (+/-201) and 1094 (+/-142) g, respectively. Intrauterine growth restricted children had fewer complications during initial hospitalization (p < 0.05), and had lower weights and head circumferences at follow-up (p < 0.05). No significant differences were present in major neurodevelopmental disabilities between the intrauterine growth restricted and two comparison groups. Persistence of microcephaly was associated with adverse neurodevelopmental outcome.