Oily fish intake during pregnancy--association with lower hyperactivity but not with higher full-scale IQ in...

Long-chain omega-3 polyunsaturated fatty acids are thought to be important for fetal neurodevelopment. Animal studies suggest that a deficiency of omega-3 fatty acids may lead to behavioural or cognitive deficits. As oily fish is a major dietary source of omega-3 fatty acids, it is possible that low intake of fish during pregnancy may have adverse effects on the developing fetal brain.

We used the Strengths and Difficulties Questionnaire and the Wechsler Abbreviated Scale of Intelligence to assess behavioural problems and intelligence in 217 nine-year-old children. The mothers of these children had participated in a study of nutrition during pregnancy during which fish intake was assessed in early and late gestation.

Children whose mothers had eaten oily fish in early pregnancy had a reduced risk of hyperactivity compared to those whose mothers did not eat oily fish: OR .34, 95% CI .15 to .78, after adjustment for potential confounding factors. Children whose mothers had eaten fish (whether oily or non-oily) in late pregnancy had a verbal IQ that was 7.55 points higher (95% CI .75 to 14.4) than those whose mothers did not eat fish. There were, however, no significant associations between fish intake in pregnancy and other behavioural problems or full-scale and performance intelligence, after adjustment for potential confounding factors.

Although maternal fish intake in pregnancy was associated with hyperactivity scores and verbal IQ in children, in general, how much fish women ate during pregnancy appeared to have little long-term relation with neurodevelopmental outcomes in their child.