Maternal lifestyle and environmental risk factors for autism spectrum disorders

Int J Epidemiol. 2014 Apr;43(2):443-64. doi: 10.1093/ije/dyt282. Epub 2014 Feb 11.


Background: Over the past 10 years, research into environmental risk factors for autism has grown dramatically, bringing evidence that an array of non-genetic factors acting during the prenatal period may influence neurodevelopment.

Methods: This paper reviews the evidence on modifiable preconception and/or prenatal factors that have been associated, in some studies, with autism spectrum disorder (ASD), including nutrition, substance use and exposure to environmental agents. This review is restricted to human studies with at least 50 cases of ASD, having a valid comparison group, conducted within the past decade and focusing on maternal lifestyle or environmental chemicals.

Results: Higher maternal intake of certain nutrients and supplements has been associated with reduction in ASD risk, with the strongest evidence for periconceptional folic acid supplements. Although many investigations have suggested no impact of maternal smoking and alcohol use on ASD, more rigorous exposure assessment is needed. A number of studies have demonstrated significant increases in ASD risk with estimated exposure to air pollution during the prenatal period, particularly for heavy metals and particulate matter. Little research has assessed other persistent and non-persistent organic pollutants in association with ASD specifically.

Conclusions: More work is needed to examine fats, vitamins and other maternal nutrients, as well as endocrine-disrupting chemicals and pesticides, in association with ASD, given sound biological plausibility and evidence regarding other neurodevelopmental deficits. The field can be advanced by large-scale epidemiological studies, attention to critical aetiological windows and how these vary by exposure, and use of biomarkers and other means to understand underlying mechanisms.

Keywords: Autism; air pollution; environmental chemicals; environmental risk factors; maternal alcohol use; maternal nutrition; maternal smoking.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Alcohol Drinking / adverse effects
  • Child Development Disorders, Pervasive / etiology*
  • Child Development Disorders, Pervasive / prevention & control
  • Environmental Pollutants / toxicity
  • Fatty Acids / administration & dosage
  • Female
  • Fetal Development / physiology
  • Fish Oils / administration & dosage
  • Fish Products
  • Folic Acid / administration & dosage
  • Humans
  • Life Style*
  • Maternal Exposure / adverse effects*
  • Preconception Care
  • Pregnancy
  • Prenatal Exposure Delayed Effects / etiology
  • Prenatal Exposure Delayed Effects / prevention & control
  • Prenatal Nutritional Physiological Phenomena / physiology
  • Risk Factors
  • Smoking / adverse effects
  • Vitamins / administration & dosage


  • Environmental Pollutants
  • Fatty Acids
  • Fish Oils
  • Vitamins
  • Folic Acid