Variation in Child Cognitive Ability by Week of Gestation Among Healthy Term Births

摘要

The authors investigated variations in cognitive ability by gestational age among 13,824 children at age 6.5 yearsnwho were born at term with normal weight, using data from a prospective cohort recruited in 1996–1997 in Belarus.nThe mean differences in the Wechsler Abbreviated Scales of Intelligence were examined by gestational age inncompleted weeks and by fetal growth after controlling for maternal and family characteristics. Compared with thenscore for those born at 39–41 weeks, the full-scale intelligence quotient (IQ) score was 1.7 points (95% confidenceninterval (CI): u00012.7, u00010.7) lower in children born at 37 weeks and 0.4 points (95% CI: u00011.1, 0.02) lower at 38 weeksnafter controlling for confounders. There was also a graded relation in postterm children: a 0.5-points (95% CI: u00012.6,n1.6) lower score at 42 weeks and 6.0 points (95% CI: u000115.1, 3.1) lower at 43 weeks. Compared with children bornnlarge for gestational age (>90th percentile), children born small for gestational age (<10th percentile) had thenlowest IQ, followed by those at the 10th–50th percentile and those at the >50th–90th percentile. These findingsnsuggest that, even among healthy children born at term, cognitive ability at age 6.5 years is lower in those born atn37 or 38 weeks and those with suboptimal fetal growth.