Prenatal Polyunsaturated Fatty Acid Levels and Risk of Autism Spectrum Disorders

Posted September 14, 2021

Kristen Lyall, Sc.D., Drexel University

Kristen Lyall, Sc.D., Drexel University
Dr. Kristen Lyall

For autism spectrum disorder (ASD), there are currently few known modifiable risk factors that can be altered by an intervention; however, evidence suggests that factors influencing early brain development are potential modifiable risk factors for ASD. Polyunsaturated fatty acids (PUFAs), which include omega 3 fatty acids, are fats that are obtained from the diet and play a critical role in early fetal neurodevelopment processes connected to the etiology of ASD. Although these fatty acids are necessary for fetal brain development during periods of rapid brain growth, research indicates that the majority of pregnant women do not meet the suggested requirements for PUFA intake during pregnancy.

The Autism Research Program (ARP) awarded Dr. Kristen Lyall a Fiscal Year 2015 Idea Development Award to examine the relationship between maternal and neonatal PUFA levels and ASD. Dr. Lyall and her team set out to determine whether levels of PUFAs, including total PUFAs, total n-6 and n-3 fatty acids, as well as specific individual fatty acids measured in maternal serum samples, differed in mothers of children later diagnosed with ASD compared to mothers of control children. This research also explored whether factors associated with maternal dietary intake, in-utero/prenatal fat processing, or other factors (i.e., race, ethnicity, pre-term birth, gestational diabetes, and child sex) modify or mediate the association of maternal prenatal PUFA levels with ASD risk.

Dr. Lyall and her research team conducted a population-based case control study that included 499 cases with ASD identified through the California Department of Developmental Services and 502 general population controls. Using prenatal serum specimens collected through routine prenatal screenings in California, Dr. Lyall’s team measured levels of PUFAs using liquid chromatography-mass spectrometry/high-resolution mass spectrometry1. Levels of PUFAs in neonatal blood spots were also measured and examined in a subset of participants2. Statistical models were used to examine the associations between maternal or neonatal PUFA levels and ASD in the child (as well as whether associations differed for ASD with our without co-occurring intellectual disability [ID]). Overall, the team did not observe strong evidence of PUFA levels influencing ASD in either maternal or neonatal samples. There was however a positive association between low total maternal PUFAs and ASD with co-occurring ID. Results from this study provided evidence suggesting that decreased maternal PUFA levels are associated with increased risk for having a child with ASD and an intellectual disability.

This study, which is one of only three studies to have measured maternal PUFA level in association with ASD-related symptoms, provided new information about the relationship between PUFAs and ASD. It is known that the majority of women who are pregnant do not reach the recommended intake levels of PUFA within their diet. Additional studies replicating these results are needed, but could be useful for dietary modifications in certain subgroups of pregnant women. The results from this study may also have a broader implication on other non-ASD neurodevelopmental disorders.


1) Lyall K, Windham GC, Snyder N, Kuskvsky R, et al. Association Between Midpregnancy Polyunsaturated Fatty Acid Levels and Offspring Autism Spectrum Disorder in a California Population-Based Case-Control Study. American Journal of Epidemiology. Feb 1;190(2):265-276. DOI: 10.1093/aje/kwaa171.

2) Bostwick A, Snyder NW, Windham GC, et al. Polyunsaturated fatty acids in newborn bloodspots: Associations with autism spectrum disorder and correlation with maternal serum levels. Autism Research. Sep;13(9):1601-1613. DOI: 10.1002/aur.2365. Epub 2020 Sep 8.


Public and Technical Abstracts: Prenatal Polyunsaturated Fatty Acid Levels and Risk of Autism Spectrum Disorders

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Last updated Thursday, May 26, 2022