Las embarazadas que comen periodicamente pescado pueden conseguir que su hijo tenga mayor inteligencia que los nacidos de madre que no lo consumen. Para conseguir el beneficio se deben comer al menos dos servicios de pescado a la semana.

Researchers have said mothers who eat fish high in omega-3 fatty acids, benefit their babies' intellectual development. Photo: Pregnant profile: Credit: mahalie/FlickrInvestigadores de la Universidad de Harvard han comprobado que hacer dos comidas semanales con pescado durante el segundo trimestre del embarazo, mejora las habilidades motoras y de lenguaje de los hijos. Además, el efecto depende del tipo de pescado ingerido. En general, se considera (y se evita) comer pescado como peligroso por los tóxicos químicos que puede contener (especialmente mercurio). Los investigadores dicen que el contenido en mercurio es poco relevante. Un segundo estudio teoriza sobre el contenido en ácidos grasos omega-3 que aporta la dieta rica en pescado.

Am J Epidemiol. 2008 Mar 18 [Epub ahead of print] Maternal Fish Intake during Pregnancy, Blood Mercury Levels, and Child Cognition at Age 3 Years in a US Cohort.Oken E, Radesky JS, Wright RO, Bellinger DC, Amarasiriwardena CJ, Kleinman KP, Hu H, Gillman MW.
Department of Ambulatory Care and Prevention, Harvard Medical School and Harvard Pilgrim Health Care, Boston, MA.

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 mother-child pairs in Massachusetts enrolled in 1999-2002, the authors studied associations of maternal second-trimester fish intake and erythrocyte mercury levels with children's scores on the Peabody Picture Vocabulary Test (PPVT) and Wide Range Assessment of Visual Motor Abilities (WRAVMA) at age 3 years. Mean maternal total fish intake was 1.5 (standard deviation, 1.4) servings/month, and 40 (12%) mothers consumed >2 servings/week. Mean maternal mercury level was 3.8 (standard deviation, 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 for fish intake of >2 servings/week versus never were 2.2 (95% confidence interval (CI): -2.6, 7.0) for the PPVT and 6.4 (95% CI: 2.0, 10.8) for the WRAVMA; for mercury in the top decile, they were -4.5 (95% CI: -8.5, -0.4) for the PPVT and -4.6 (95% CI: -8.3, -0.9) for the WRAVMA. Fish consumption of </=2 servings/week was not associated with a benefit. Dietary recommendations for pregnant women should incorporate the nutritional benefits as well as the risks of fish intake.