Prenatal infection and autism spectrum disorders in childhood: A population-based case-control study in Taiwan

Background Infection in pregnancy has long been linked with negative postnatal development and health. This study aims to assess the association between prenatal infections and autism spectrum disorders (ASDs) across three trimesters and to probe possible sex heterogeneity in such link. Method A total of 4184 children with incident ASDs and 16-734 matched children were identified from the 2000-2007 National Health Insurance Research Database. For each child, information pertaining to the mother's infection during pregnancy, sociodemographics, and medical history was retrieved from healthcare records. Conditional logistic analyses were carried out to estimate the strength of associations with adjustment for multiple comparisons. Result Pooled analyses demonstrated that having two or more outpatient visits for genital infection [adjusted odds ratio (aOR): 1.34; 95% confidence interval (95% CI) 1.12, 1.60; false discovery rate (FDR)-<-0.01] and bacterial infection (aOR: 1.24; 95% CI 1.06, 1.43; FDR-<-0.05) in the third trimester were slightly associated with increased risk of ASDs. No statistically significant sex differences were found. Conclusion The present study contributes updated population-based evidence about the connection between prenatal infection and ASDs. Potential effect of bacterial and genital tract infections during the third trimester on risk of ASDs warrants further exploration.