Autism

STUDY: PRETERM AND EARLY TERM BIRTHS LINKED TO HIGHER RISKS OF AUTISM SPECTRUM DISORDER

A Swedish study of more than 4 million people born between 1973 and 2013 found significantly higher risks of autism among those born preterm or early term, independent of shared genetic or environmental factors. The study, “Preterm or Early Term Birth and Risk of Autism,” published in the September 2021 Pediatrics (published online Aug. 11) found prevalence rates of autism spectrum disorder were inversely related to gestational age at birth; 6.1 % for extremely preterm (22–27 weeks), 2.6% for very to moderate preterm (28–33 weeks), 1.9 % for late preterm (34–36 weeks), 1.6 % for early term (37–38 weeks) and 1.4% full term (39–41 weeks). After controlling for other perinatal and parental differences, the prevalence of autism was nearly 4-fold higher in persons born extremely preterm, 40% higher in those born preterm, and 10-15% higher in those born early term, compared with those born full term. These increased risks were seen among both males and females, and comparisons of siblings showed that they were largely not explained by shared genetic or environmental factors within families. The authors suggest that infants born prematurely need early evaluation and long-term follow-up to facilitate timely detection and treatment of autism spectrum disorder, especially those born at the earliest gestational ages.