Symptoms and antecedents of autism in children born extremely premature: a national population-based study

The objective of this study is to investigate the prevalence of autism (ASD) symptoms, i.e. , social difficulties, repetitive behaviors, and communicational problems, among children born extremely preterm (EP) compared to a reference group, and to investigate possible antecedents of ASD symptoms among EP children. Method is a national Norwegian cohort of 11 year old EP children, excluding those with intellectual disabilities, non-ambulatory cerebral palsy, blindness, and/or deafness. Parents and teachers reported ASD symptoms using The Autism Spectrum Screening Questionnaire (ASSQ). Social difficulties, repetitive behaviors, communicational problems, and a total ASSQ score were presented. Combined ratings on the ASSQ was defined as parent and/or teacher scoring the child ≥ 98th percentile of the reference group, which was the population-based Bergen Child Study. Of eligible children, 216 (64%) EP and 1882 (61%) reference children participated. EP children had significantly higher mean scores and combined ratings on social difficulties (14.5% vs. 4.1%, OR: 3.2), repetitive behaviors (23.7% vs. 4.0%, OR: 6.4), communicational problems (23.1% vs. 4.8%, OR: 5.4), and the total ASSQ score (18.3% vs. 3.4%, OR: 5.7) compared to reference children. Only no prenatal steroids, IQ 70–84, and mental health problems at 5 years of age were significantly associated with ASD symptoms at 11 years of age. EP children were at increased risk of social difficulties, repetitive behaviors, and communicational problems, and approximately one out of five were reported as high scorers of ASD symptoms. No prenatal steroids use, IQ in the lower range, and mental health problems at 5 years of age were associated with ASD symptoms. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00787-022-01953-4.