Behavioral outcomes of school-aged full-term small-for-gestational-age infants: A nationwide Japanese population-based study

Background Small for gestational age (SGA) birth is linked with neurological deficits among children at pre-school age, but the evidence is still limited on whether such deficits are still observable at school age. We investigated the association between SGA birth and behavioral development at school age among full-term infants. Methods We analyzed data from a large, Japanese, nationwide, population-based longitudinal survey that started in 2001. We restricted the study participants to children born at 37–41 weeks of gestation with information on birth weight and behavioral outcomes at 8 years of age (n = 33,795). Behavioral outcomes including three attentional problems and four aggressive behaviors queried at 8 years of age by survey questions were used as outcome indicators. We then used logistic regression to estimate odds ratios (OR) and 95% confidence intervals (95% CI) for the associations between SGA birth and each outcome, adjusting for potential infant- and parent-related confounding factors. Results Among full-term children, SGA children were more likely to interrupt people (OR 1.10, 95% CI 1.01, 1.20), unable to wait his/her turn (OR 1.17, 95% CI 1.00, 1.38), and destroy toys and/or books (OR 1.15, 95% CI 1.00, 1.31). Conclusions This is the largest study ever conducted on this issue. SGA birth is negatively associated with some attentional problems and aggressive behavior at school age among full-term children. Appropriate long-term developmental follow-up and support may be needed for full-term SGA infants.