Gardener, H.Spiegelman, D.Buka, S. L.2019-09-212009Gardener, Hannah, Donna Spiegelman, and Stephen L. Buka. 2009. “Prenatal Risk Factors for Autism: Comprehensive Meta-Analysis.” British Journal of Psychiatry 195 (1): 7–14. https://doi.org/10.1192/bjp.bp.108.051672.0007-12501472-1465http://nrs.harvard.edu/urn-3:HUL.InstRepos:41384658BackgroundThe aetiology of autism is unknown, although prenatal exposures have been the focus of epidemiological research for over 40 years.AIMSTo provide the first quantitative review and meta-analysis of the association between maternal pregnancy complications and pregriancy-related factors and risk of autism.MethodPubMed, Embase and PsycINFO databases were searched for epidemiological studies that examined the association between pregnancy-related factors and autism. Forty studies were eligible for inclusion in the meta-analysis. Summary effect estimates were calculated for factors examined in multiple studies. Results: over 50 prenatal factors have been examined. The factors associated with autism risk in the meta-analysis were advanced parental age at birth, maternal prenatal medication use, bleeding, gestational diabetes, being first born v. third or later, and having a mother born abroad. The factors with the strongest evidence against a role in autism risk included previous fetal loss and maternal hypertension, proteinuria, pre-eclampsia and swelling. Conclusions: There is insufficient evidence to implicate any one prenatal factor in autism aetiology, although there is some evidence to suggest that exposure to pregnancy complications may increase the risk.en-USJournal Article2019-09-2110.1192/bjp.bp.108.051672