Mid-Pregnancy Polyunsaturated Fatty Acid Levels in Association with Child Autism Spectrum Disorder in a California Population-Based Case-Control Study.

Polyunsaturated fatty acids (PUFAs) are critical for brain development and have been linked with neurodevelopmental outcomes. We conducted a population-based case control study in California to examine the association between PUFAs measured in mid-pregnancy serum samples and child autism spectrum disorder (ASD). ASD cases (n = 499) were identified through the Department of Developmental Services and matched to live-birth population controls (n = 502) on birth month, year (2010-2011), and sex. Crude and adjusted logistic regression models were used to examine associations. Secondary analyses examined ASD with and without co-occurring intellectual disability (ID; n = 67 and 432 respectively), and effect modification by sex and ethnicity. No clear patterns emerged, though there was a modest inverse association with the top quartile of linoleic acid (highest versus lowest quartile, adjusted OR = 0.74, 95% CI: 0.49, 1.11; P for trend = 0.10). Lower levels of total and ω 3 PUFAs were associated with ASD with ID (lowest decile versus deciles 4-7, total PUFA adjusted OR = 2.78 95% CI: 1.13, 6.82) but not ASD without ID. We did not observe evidence of effect modification by factors examined. Findings do not suggest a strong association between mid-pregnancy PUFA levels and ASD. Further work should consider associations with ASD with ID and in other time windows.