Maternal Fish Intake during Pregnancy, Blood Mercury Levels, and Child Cognition at Age 3 Years in a US Cohort

Abstract

The balance of contaminant risk and nutritional benefit from maternal prenatal fish consumption for child cognitive development is not known. Using data from a prospective cohort study of 341 motherchild pairs, authors studied associations of maternal 2 nd trimester fish intake and erythrocyte mercury levels with child age 3 year scores on the Peabody Picture Vocabulary Test (PPVT) and Wide-Range Assessment of Visual Motor Abilities (WRAVMA). Mean maternal total fish intake was 1.5 (SD 1.4) servings/month, and 40 (12%) of mothers consumed > 2 weekly fish servings. Mean (SD) maternal mercury was 3.8 (3.8) ng/g. After adjustment using multivariable linear regression, higher fish intake was associated with better child cognitive test performance, and higher mercury levels with poorer test scores. Associations strengthened with inclusion of both fish and mercury: effect estimates (95% CI) for fish intake > 2 servings/week vs. never were 2.2 (−2.6, 7.0) for PPVT and 6.4 (2.0, 10.8) for WRAVMA; and for mercury in the top decile, −4.5 (−8.5, −0.4) for PPVT and −4.6 (−8.3, −0.9) for WRAVMA. Fish consumption <= 2 weekly servings was not associated with a benefit. Dietary recommendations for pregnant women should incorporate the nutritional benefits as well as the risks of fish intake.

Current Information and Asian Perspectives on Long-Chain Polyunsaturated Fatty Acids in Pregnancy, Lactation, and Infancy: Systematic Review and Practice Recommendations from an Early Nutrition Academy Workshop

“…In several observational cohort studies, beneficial effects of n-3 or fish intake during pregnancy and/or lactation on the developmental outcomes and cognition of the offspring up to 14 years of age have been reported, even after adjusting for potential confounding factors [28,29,30]. …”

Mercury health risk assessment among a young adult Lebanese population

“…In addition, both higher blood Hg concentrations and increased maternal fish consumption in the second trimester were associated with lower scores in cognitive and visual abilities among children in a US prospective cohort study (Oken et al 2008). While fetal brain seems to be more susceptible to Hg toxicity, a major concern for adults involves evidence of Hg antagonizing the positive cardio-protective effects of omega-3 fatty acids, which is also normally acquired through fish consumption (Yoshizawa et al 2002).…”

The effect of maternal omega-3 (n-3) LCPUFA supplementation during pregnancy on early childhood cognitive and visual development: a systematic review and meta-analysis of randomized controlled trials

“…Observational studies have reported that consumption of oily fish, which is known to be rich in omega-3 LCPUFAs, during pregnancy is positively associated with high-grade stereoacuity (13), vocabulary comprehension (14), receptive vocabulary (15), and verbal intelligence quotient (16,17) from infancy to 9 y of age and that pregnant women who consume higher than the recommended quantity of fish have children with higher cognitive scores (17,18). However, such observational studies are unable to establish causality because of the difficulty in adjusting for complex confounding factors that also influence early child development (19).…”