Aim: To investigate whether infants born late preterm have poorer cognitive outcomes than term-born infants.
Method: A cohort study based on the Avon Longitudinal Study of Parents and Children. Cognitive measures were assessed between the ages of 8 and 11 years. Exposure groups were defined as moderate/late preterm (32-36 weeks' gestation) or term (37-42 wk). Regression models were used to investigate the association between gestational age and IQ.
Results: Seven hundred and forty-one infants (5.4% of total eligible population; 422 males, 319 females; mean (SD) birthweight 2495 g [489]) were born between 32 and 36 weeks' gestation. The analysis was based on 6957 infants with IQ data at age 11 (50% of eligible infants). In the adjusted model, children born moderately and late preterm had similar IQ scores to peers born at term (mean difference [95% confidence interval] -0.18 [-1.88 to 1.52]). However, the preterm infants had a higher risk of having special educational needs at school (odds ratio 1.56 [1.18-2.07]).
Interpretation: Despite an increased risk of special educational needs, there is little evidence of a reduction in IQ, memory, or attention measures at school age in children born between 32 and 36 weeks' gestation. Although interpretation is limited by the amount of missing data, further work is needed to identify why these infants have increased educational needs.
© The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.