Gestational Age and Kindergarten School Readiness in a National Sample of Preterm Infants

Objective To examine the association of gestational age with school readiness in kindergarten reading and math skills. We hypothesized that compared with infants born at 39-41 weeks, infants born at lower gestational ages would have poorer school readiness. Study design The study sample comprised 5250 children from the Early Childhood Longitudinal Study, Birth Cohort, assessed with specialized reading and math assessments at kindergarten. Poor school readiness was characterized by reading and math theta scores >= 1.5 SD below the sample mean. The aOR and 95% CI of poor school readiness were estimated using multivariate logistic regression, examining gestational age continuously and categorically (very preterm [VPT], moderate/late preterm [M/LPT], early term [ET], and term). Pairwise comparisons were performed to test for differences by gestational age category. Results There was an association between gestational age and poor school readiness for reading and math, with the suggestion of a threshold effect in children born at >= 32 weeks gestation. In adjusted models, in VPT infants, the aORs of poor school readiness in reading and math were 2.58 (95% CI, 1.29-5.15) and 3.38 (95% CI, 1.66-6.91), respectively. For infants born M/LPT and ET, the odds of poor school readiness in reading did not differ from those of children born full-term, however. Conclusions Compared with term infants, the highest odds of poor school readiness in reading and math were seen in VPT infants, with lower odds of poor school readiness in children born at >= 32 weeks gestation. Ongoing developmental surveillance before kindergarten is indicated for VPT infants.