We assessed auditory event-related potentials in small-forgestational-age (SGA; 850 Ϯ 258 g, 28.9 Ϯ 3.3 gestational wk; n ϭ 15) and appropriate for gestational age (AGA; 1014 Ϯ 231 g, 26.9 Ϯ 1.9 gestational wk; n ϭ 20) preterm infants and healthy term infants (n ϭ 22). An oddball paradigm was used with a harmonic tone of 500-Hz frequency as the standard and of 750-Hz frequency as the deviant stimulus. The preterm infants were studied at 40 gestational wk and at 6 and 12 mo of corrected age, and the control subjects were studied at 2-4 d and at 3, 6, 9, 12, and 15 mo of age. The peaks of interest were the main positive peak (P350), the negative peaks at 250 ms (N250) and 650 ms (Nc), and the mismatch negativity at 200 ms (MMN). At term, the P350 in the preterm infants was similar to that of the newborn control subjects. In response to the deviant, the Nc was smaller in the SGA than in the AGA (P Ͻ 0.02) and control (P Ͻ 0.005) infants. The N250 amplitude was also lower in the SGA infants. At 12 mo, the MMN was observed in the control but not in the preterm infants, whose broad difference positivity correlated with the Bayley developmental index. The decreased Nc and N250 peaks in the SGA infants may suggest an increased risk for cognitive dysfunction. The broad difference positivity at 1 y of age may indicate atypical cortical auditory processing. Whether cognitive dysfunction can be predicted by these findings needs to be assessed in a study with extended follow-up. The survival of very low birth weight infants (VLBWI; birth weight Ͻ1500 g) has significantly improved during the last two decades, especially of those with a gestational age Ͻ28 wk (1,2). The impairment rate has remained similar or only slightly decreased, thus resulting in an increased absolute number of infants with neurodevelopmental abnormalities (3,4). In very preterm infants, the rate of severe handicap, such as cerebral palsy, deafness, blindness, and mental retardation, has in recent studies varied from 15 to 25% (1,3). Cognitive dysfunction and learning disabilities are even more common.In a large VLBWI birth cohort study in the Netherlands, at the age of 9 y, 56% of children in mainstream education needed special assistance at school or were below the age-appropriate level (5). Similar results have been reported from other countries (6).Several perinatal risk factors have been associated with poor school performance, such as low birth weight, intraventricular hemorrhage, and need for assisted ventilation (7). Intrauterine growth restriction in preterm infants is associated with increased morbidity, both in the neonatal period and later on; the risk for neurosensory abnormalities is increased compared with appropriately grown preterm infants (8). In a previous study, (9) we showed that growth-retarded VLBWI born in the mid1980s had a poorer neuropsychological performance at 7 y of age than appropriately grown control children.Although both perinatal risk factors and abnormal neurologic signs early in infancy may be associated with later cog...
