Severe small size for gestational age and cognitive function: catch-up phenomenon possible.

Abstract

We sought to compare cognitive functioning in children born with birthweight <3% vs ≥3% for gestational age (GA) between 9 months and kindergarten. Nonanomalous singletons from the Early Childhood Longitudinal Study-Birth Cohort were included. Associations between weight for GA and cognitive functioning were examined using a series of confounder-adjusted general linear models. Of 3633 cohorts, 585 (16%) were <3% for GA. At 9 months, cognitive performance of newborns <3% was about 12 percentile points lower than their normal counterparts (P < .001). By 2 years, however, no significant cognitive differences between these groups were observed (P = .668). Academic performance at preschool age (around 3.5 years) was not different for reading (P = .245) or math (P = .880), nor different at kindergarten age. Newborns <3% for GA exhibit catch-up cognitive functioning by 2 years, with relatively no decrements in academic functioning observed by kindergarten.