Maternal Fatty Acid Status During Pregnancy and Child Autistic Traits

ω-3 and ω-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 ω-3:ω-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 ω-3:ω-6 ratio during pregnancy was associated with more autistic traits in the offspring (β = −0.008, 95% confidence interval: −0.016, −0.001). In particular, a higher total ω-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 ω-3 status was not associated with child autistic traits and, consistently, neither was prenatal dietary fish intake. Our study shows that a lower prenatal ω-3:ω-6 ratio is associated with more child autistic traits, which is largely accounted for by higher ω-6 instead of lower ω-3 status. These results suggest a biological pathway between maternal fatty acid intake during pregnancy and autistic traits in the offspring.