Maternal Fatty Acid Status During Pregnancy and Child Autistic Traits

omega-3 and omega-6 polyunsaturated fatty acids are important for brain function and development. We examined whether maternal polyunsaturated fatty acid status during pregnancy affects risk of autistic traits in childhood. Within the Generation R cohort, we measured maternal plasma polyunsaturated fatty acid concentrations and the omega-3:omega-6 ratio in midpregnancy (Rotterdam, the Netherlands, 2001-2005). Child autistic traits at 6 years were assessed by using the Social Responsiveness Scale short form in 4,624 children. A lower maternal omega-3:omega-6 ratio during pregnancy was associated with more autistic traits in the offspring (beta = -0.008, 95% confidence interval: -0.016, -0.001). In particular, a higher total omega-6 and linoleic acid status were associated with more autistic traits (all P's < 0.05). Associations were independent of child intelligence, suggesting that the fatty acid distribution specifically affects the development of autistic traits in addition to general neurodevelopment. Maternal plasma omega-3 status was not associated with child autistic traits and, consistently, neither was prenatal dietary fish intake. Our study shows that a lower prenatal omega-3:omega-6 ratio is associated with more child autistic traits, which is largely accounted for by higher omega-6 instead of lower omega-3 status. These results suggest a biological pathway between maternal fatty acid intake during pregnancy and autistic traits in the offspring.