Perinatal and maternal risk factors for autism spectrum disorders in New South Wales, Australia

Abstract

Background: This study was commenced in 1999 with the aim of examining risk factors for autism using established population-based data for comparison. Methods: Cases were ascertained using active surveillance and compared with birth data. Results: Four risk factors were found to be significantly associated with autism using binary logistic regression analysis; being male [adjusted odds ratio (OR) 4.7, 95% confidence interval (CI) 3.2-7.0], being born prematurely (adjusted OR 2.2, 95% CI 1.5-3.5), having maternal age ≥35 years (adjusted OR 1.7, 95% CI 1.2-2.4) and having a mother born outside Australia (adjusted OR 1.4, 95% CI 1.0-1.9). For analysis completed for pregnancies, rather than live..