HealthDay News — Preterm and early-term births are associated with an increased risk for autism spectrum disorder (ASD) among boys and girls, according to a study published online Aug. 11 in Pediatrics.
Casey Crump, M.D., Ph.D., from the Icahn School of Medicine at Mount Sinai in New York City, and colleagues examined the association of preterm and early-term birth with ASD in a national cohort study of all 4,061,795 singletons born in Sweden during 1973 to 2013 who survived to age 1 year. Participants were followed up for ASD through 2015.
The researchers found that the prevalence of ASD was 6.1, 2.6, 1.9, 2.1, 1.6, and 1.4 percent for extremely preterm (22 to 27 weeks), very to moderate preterm (28 to 33 weeks), late preterm (34 to 36 weeks), all preterm (<37 weeks), early-term (37 to 38 weeks), and full-term (39 to 41 weeks) births, respectively. Compared with term births, extremely preterm, all preterm, and early-term births yielded adjusted prevalence ratios for ASD of 3.72, 1.35, and 1.11, respectively, among boys and 4.19, 1.53, and 1.16, respectively, among girls. After controlling for shared familial factors, these associations were only slightly attenuated.
“These findings were largely independent of measured covariates and unmeasured shared familial factors, consistent with a potential causal relationship,” the authors write. “Persons born prematurely need early evaluation and long-term follow-up to facilitate timely detection and treatment of ASD, especially those born at the earliest gestational ages.”