Birth defects in children with autism spectrum disorders: a population-based, nested case-control study.

Area of Science:

• Neurodevelopmental Disorders
• Pediatric Health
• Genetics and Environmental Science

Background:

• The etiology of autism spectrum disorders (ASDs) remains largely unknown, with genetic and environmental factors implicated.
• Previous research has suggested a link between birth defects and ASDs, but associations with specific diagnostic subtypes are less understood.

Purpose of the Study:

• To investigate the association between birth defects and specific diagnostic categories of ASD, including autism, Asperger syndrome, and pervasive developmental disorder not otherwise specified.
• To compare the prevalence of birth defects in children with ASD, their siblings, and population controls.

Main Methods:

• A nested case-control study utilizing Western Australian population-based linked data.
• Comparison of 465 children with ASD born between 1980-1995 with 481 siblings and 1,313 population controls.
• Statistical analysis to determine odds ratios for birth defects in ASD cases, adjusted for confounding factors.

Main Results:

• The prevalence of birth defects was significantly higher in ASD cases compared to population controls, even after adjustment.
• Odds ratios for birth defects were elevated for autism (OR=2.0) and pervasive developmental disorder not otherwise specified (OR=2.2), but not for Asperger syndrome (OR=0.5).
• No significant difference in birth defect prevalence was observed between case siblings and either cases or population controls.

Conclusions:

• A significant association exists between birth defects and autism spectrum disorders.
• This association may stem from common underlying genetic and/or environmental factors influencing both conditions.
• Alternatively, birth defects might increase the risk or predisposition to developing ASD.