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Parental and Perinatal Risk Factors for Autism: Epidemiological Findings and Potential Mechanisms

Research output: Chapter in Book/Report/Conference proceedingChapter

Sven Sandin, Alexander Kolevzon, Stephen Z. Levine, Christina M. Hultman, Abraham Reichenberg

Original languageEnglish
Title of host publicationThe Neuroscience of Autism Spectrum Disorders
Number of pages8
ISBN (Print)9780123919243
Publication statusPublished - 27 Aug 2013

King's Authors


There is evidence that non-heritable familial pre- or perinatal factors play a role in the etiology of autism and autism spectrum disorders (ASD). According to current evidence from epidemiological studies, two groups of factors show a consistent relationship with ASD: advancing parental age and preterm birth and intrauterine growth restriction. Using a systematic review and meta-analysis of epidemiological studies incorporating a comprehensive assessment of risk factors, we have examined the evidence for an association between advancing parental age, low birth weight, preterm birth and being born small for gestational age, and risk for ASD in the offspring. Advancing maternal age (35 or older), and paternal age (40 or older), show a consistent relationship with ASD. Current evidence also supports a relationship between low birth weight (< 2,500 grams), preterm birth (< 37 weeks) and being born small for gestational age, and ASD. Future research should continue to examine these variables using large, population-based cohorts in order to offer a more refined modeling of risk and potential confounders, and to attempt to distinguish between autism and spectrum disorders. Identifying common and unique risk factors may be important to understand shared and non-shared etiologies.

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