Maternal Fish Consumption, Hair Mercury, and Infant Cognition in a U.S. Cohort Emily Oken,1 Robert O. Wright,2,3 Ken P. Kleinman,1 David
Bellinger,4,5 Chitra J. Amarasiriwardena,3
Howard Hu,3,5 Janet W. Rich-Edwards,1,6 and Matthew W.
Gillman1,7 1Department of Ambulatory Care and Prevention, Harvard Medical School
and Harvard Pilgrim Health Care, Boston, Massachusetts, USA; 2Department
of Pediatrics, Boston Children’s Hospital and Harvard Medical School,
Boston, Massachusetts, USA; 3Channing Laboratory, Brigham and Women’s
Hospital and Harvard Medical School, Boston, Massachusetts, USA; 4Department
of Neurology, Boston Children’s Hospital and Harvard Medical School,
Boston, Massachusetts, USA; 5Department of Environmental Health, 6Department
of Epidemiology, and 7Department of Nutrition, Harvard School of
Public Health, Boston, Massachusetts, USA Abstract Fish and other seafood may contain organic mercury but also beneficial nutrients such as n-3 polyunsaturated fatty acids. We endeavored to study whether maternal fish consumption during pregnancy harms or benefits fetal brain development. We examined associations of maternal fish intake during pregnancy and maternal hair mercury at delivery with infant cognition among 135 mother-infant pairs in Project Viva, a prospective U.S. pregnancy and child cohort study. We assessed infant cognition by the percent novelty preference on visual recognition memory (VRM) testing at 6 months of age. Mothers consumed an average of 1.2 fish servings per week during the second trimester. Mean maternal hair mercury was 0.55 ppm, with 10% of samples > 1.2 ppm. Mean VRM score was 59.8 (range, 10.9-92.5) . After adjusting for participant characteristics using linear regression, higher fish intake was associated with higher infant cognition. This association strengthened after adjustment for hair mercury level: For each additional weekly fish serving, offspring VRM score was 4.0 points higher [95% confidence interval (CI) , 1.3 to 6.7]. However, an increase of 1 ppm in mercury was associated with a decrement in VRM score of 7.5 (95% CI, -13.7 to -1.2) points. VRM scores were highest among infants of women who consumed > 2 weekly fish servings but had mercury levels ≤ 1.2 ppm. Higher fish consumption in pregnancy was associated with better infant cognition, but higher mercury levels were associated with lower cognition. Women should continue to eat fish during pregnancy but choose varieties with lower mercury contamination. Key words: child development, cognition, environmental health, fish, mercury, n-3 fatty acids, neurotoxins, seafood. Environ Health Perspect 113: 1376-1380 (2005) . doi:10.1289/ehp.8041 available via http://dx.doi.org/ [Online 26 May 2005] Address correspondence to E. Oken, Department of Ambulatory Care and Prevention, Harvard Medical School and Harvard Pilgrim, 133 Brookline Ave., Boston, MA 02215 USA. Telephone: (617) 509-9835. Fax: (617) 859-8112. E-mail: emily_oken@harvardpilgrim.org We appreciate the invaluable contributions provided to this project by the staff and participants of Project Viva. This project was supported by grants from the National Institutes of Health (HD34568, HL68041, HD44807, ES00002, P01ES012874) , Harvard Medical School, and the Harvard Pilgrim Health Care Foundation. The authors declare they have no competing financial interests. Received 24 February 2005 ; accepted 26 May 2005. The full version of this article is available for free in HTML or PDF formats. |