Neurobehavioral outcomes of school-age children born extremely low birth weight or very preterm in the 1990s

Context The outcome into school age of regional cohorts of children born in the 1990s with birth weights less than 1000 g (extremely low birth weight, ELBW) or earlier than 28 weeks' gestation (very preterm) is not known. Objective To determine the cognitive, educational, and behavioral outcome of ELBW or very preterm infants born in the 1990s compared with normal birth weight (NBW) controls. Design Regional cohort study. Setting Victoria, Australia. Participants The ELBW or very preterm cohort was composed of 298 consecutive survivors born during 1991-1992. The NBW cohort was composed of 262 randomly selected children with birth weights of more than 2499 g. Main Outcome Measures Cognitive ability, educational progress, and behavioral problems. Results The follow-up rates from birth to 8 years of age for survivors were 92.3% (275/298) for the ELBW or very preterm cohort and 85.1% (223/262) for the NBW cohort. The ELBW or very preterm children scored significantly below NBW controls on full-scale IQ (mean difference, -9.4; 95% confidence interval [CI], -12.1 to -6.7; P<.001) and indices of verbal comprehension (mean difference, -6.8; 95% Cl, -9.5 to -4.2; P<001), perceptual organization (mean difference, -9.9; 95% Cl, -12.7 to -7.2; P<001), freedom from distractibility (mean difference, -8.1; 95% Cl, -10.8 to -5.5; P<001), and processing speed (mean difference, -6.7; 95% Cl, -9.4 to -4.0; P<001). The ELBW or very preterm children performed significantly worse than the NBW cohort on tests of reading (mean difference, -6.7; 95% Cl, -9.5 to -3.9; P<001), spelling (mean difference, -5.6; 95% Cl, -8.0 to -3.3; P<.001), and arithmetic (mean difference, -8.8; 95% Cl, -11.3 to -6.2; P<.001). Attentional difficulties, internalizing behavior problems, and immature adaptive skills were more prevalent in the ELBW or very preterm cohort. Conclusion School-aged ELBW or very preterm children born in the 1990s continue to display cognitive, educational, and behavioral impairments.