Federal guidelines for Americans recommend that pregnant people eat at least two to three servings of seafood per week to support fetal brain development. Yet in the United States, prenatal fish consumption is generally low.

Research from Drexel’s A.J. Drexel Autism Institute, Harvard Medical School, and Harvard Pilgrim Health Care Institute continues previous work that has found eating fish, but not omega-3 supplement use, may be associated with a lower likelihood of autism diagnosis and related traits in children. Autism is a developmental disorder with many causes; genetics play a strong role.

Researchers analyzed data from 10,800 pregnancies across 23 National Institutes of Health (NIH) research sites for fish consumption and 12,646 pregnancies across 35 sites for omega-3 supplement use, comparing these factors with clinician-diagnosed autism and autism-related traits reported by parents or caregivers. Information was collected between 1999 and 2020.

Despite the health benefits of fish consumption, about a quarter of study participants reported eating no fish during pregnancy, and even fewer reported taking omega-3 supplements.

Kristen Lyall, associate professor in the A.J. Drexel Autism Institute, and co-author Emily Oken, MD, a professor in Harvard Medical School and Harvard Pilgrim Health Care Institute, believe these findings indicate a need for better public health messaging.

“This study provides yet more evidence for the safety and benefit of regular fish consumption during pregnancy,” says Oken. “Other proven benefits include lower risk for preterm birth and improved cognitive development. Pregnant people should aim to consume a variety of fish types at least twice weekly.”

The study was funded by the NIH’s Environmental Influences on Child Health Outcomes program and published in The American Journal of Clinical Nutrition.