Gestational age at term and educational outcomes at age nine

Objectives: To estimate associations between gestational age (GA) and teacher-reported academic outcomes at age 9 years among children born at term (37-41 weeks). Methods: A secondary data analysis of 1405 children participating in a national US birth cohort study was conducted. At age 9 years, students were evaluated by their teachers in the areas of mathematics, science and social studies, and language and literacy. Unadjusted and adjusted logistic regression models of associations between GA and teacher-reported academic outcomes were estimated and neonatal morbidities were explored as potential pathways. Results: A continuous measure of GA in weeks was significantly associated with above-average rankings in all areas. The associations were similar across outcomes (eg, mathematics [odds ratio (OR): 1.13; confidence interval (CI): 1.02-1.25], science and social studies [OR: 1.13; CI: 1.01-1.26], and language and literacy [OR: 1.16; CI: 1.05-1.28]) in a model that adjusted for child sex, maternal characteristics, and obstetric risk factors and delivery complications. Other specifications indicate a positive association between late term (41 weeks) and mathematics and a negative association between early term (37-38 weeks) and language and literacy, compared with term (39-40). The associations did not appear to operate through neonatal morbidity. Conclusions: The findings highlight the importance of GA, even at term. Whereas current guidelines suggest waiting until at least 39 weeks to deliver when possible, our findings add to a small group of studies suggesting that GA through 41 weeks is associated with improvements in some educational outcomes.