Autistic traits of children born very preterm assessed using Autism Diagnostic Observation Schedule, Second Edition.

Preterm birth has been linked with increased incidence of autism spectrum disorder (ASD). Despite the remarkable difference in the clinical backgrounds between ASD children born preterm and term, cross-sectional studies have found no striking difference in their autistic traits. To highlight autistic traits related with preterm birth, children born very preterm (prospective birth cohort, n = 50) and term (case cohort, n = 16), who were diagnosed as "Autism" by the Autism Diagnostic Observation Schedule (ADOS), 2nd edition, were compared using the calibrated severity scores of ADOS-2 and T-scores of the Social Responsiveness Scale, 2nd edition. No significant difference was found in the calibrated severity scores between ASD children born preterm and term. There was a trend that T-scores were smaller for the preterm cohort, which did not reach a statistical significance. Even when detailed cross-sectional information was obtained using ADOS-2, no difference in autistic traits was observed between children born very preterm and term. Our findings were consistent with a previous study, which assessed the entire prospective cohort of children born very preterm and found no difference in original ADOS scores. Further studies are warranted to delineate how preterm birth affects the autistic traits and their parental perception in a large prospective cohort.