Seafood consumption during pregnancy is thought to be beneficial for child neuropsychological development, but few, if any, large cohort studies with high fatty fish consumption have analyzed the association by seafood subtype. Researchers evaluated 1,892 and 1,589 mother-child pairs at the ages of 14 months and 5 years, respectively, in a population-based Spanish birth cohort established during 2004 to 2008. Their findings were published in the American Journal of Epidemiology.

Bayley and McCarthy scales and the Childhood Asperger Syndrome Test were used to assess neuropsychological development. Results from multivariate linear regression models were adjusted for sociodemographic characteristics and further adjusted for umbilical cord blood mercury or long-chain polyunsaturated fatty acid concentrations.

Overall, researchers found consumption of seafood above the recommended limit of 340 grams/week was associated with 10-gram/week increments in neuropsychological scores. By subtype, in addition to lean fish, consumption of large fatty fish showed a positive association; offspring of persons within the highest quantile (>238 g/week) had an adjusted increase of 2.29 points in McCarthy general cognitive score (95% confidence interval: 0.42, 4.16). Similar findings were observed for the Childhood Asperger Syndrome Test. Beta coefficients diminished 15-30% after adjustment for mercury or long-chain polyunsaturated fatty acid concentrations.

Researchers concluded that consumption of large fatty fish during pregnancy presents moderate child neuropsychological benefits, including improvements in cognitive functioning and some protection from autism-spectrum traits.