Gestational Age in Autistic Children and Adolescents: Prevalence and Effects on Autism Phenotype.

This study looked at when autistic children were born compared to other children. Researchers found that autistic children were more likely to be born either early (before 37 weeks) or late (after 42 weeks) than children without autism. Children born late had the highest chance of being autistic. However, the timing of birth didn't seem to change how autism showed up in these children - their autistic traits were similar regardless of when they were born.

This Dutch population study examined gestational age patterns in 606 autistic children and adolescents compared to matched controls from birth registers. The research found higher prevalence of both pre-term (before 37 weeks) and post-term (after 42 weeks) births among autistic individuals, with particularly elevated autism risk for post-term children. The study used validated questionnaires (AQ-short and SDQ) to assess autism characteristics and comorbid symptoms. Importantly, no phenotypical differences in autism presentation were found across different gestational age groups, suggesting that while birth timing affects autism risk, it doesn't significantly influence the expression of autistic traits once autism is present.

Findings support enhanced autism screening for children born pre-term or post-term, particularly those born after 42 weeks. Results suggest gestational age timing influences autism risk but not symptom presentation, informing both prevention strategies and clinical expectations for autism phenotype across birth timing groups.

Single-country study limiting generalizability. Study type not specified, potentially affecting methodological rigor. Sample characteristics beyond basic demographics not fully detailed. Causality cannot be established from this observational design.

Pre- and post-term children show increased autism risk. Little is known about gestational age (GA) prevalence among autistic children, and their respective autism phenotype. We compared prevalence of pre-, full- and post-term birth between a population-derived sample of N = 606 (137 females, 22.61%) autistic children and adolescents (mean age = 14.01, SD = 3.63, range 3-24) from the Netherlands Autism Register, and matched controls from the Dutch birth register. Autism phenotype and comorbid symptoms were assessed with the AQ-short and SDQ questionnaires.

Using logistic regression, we found higher prevalence of pre- and post-term birth among autistic individuals but no phenotypical differences across GA groups. Autism risk was particularly elevated for post-term children, highlighting the need for closer investigation of autism on the whole GA range.