DHA in Pregnancy Had No Impact on Child IQ - study

Docosahexaenoic acid (DHA) supplements during pregnancy had no significant impact on either IQ or cognition scores of children compared to mothers who received placebo, a small randomized trial in Australia found.

There was no significant difference between the mean IQ of DHA and control groups for children at age 7 years (98.31 versus 97.32, adjusted mean difference 1.30, 95% CI -0.47 to 3.08, P=0.15), reported Jacqueline F. Gould, BoSc, of the South Australian Health and Medical Research Institute, and colleagues.

The authors also noted that while perceptual reasoning scores in the DHA group were "slightly higher," there was no significant difference in performance on measures of language, academic functioning, and executive functioning, they wrote in a research letter in the Journal of the American Medical Association (JAMA).

Gould and colleagues argued that the sale of these prenatal supplements with DHA "continues to increase, despite little evidence of benefit to offspring neurodevelopment," they wrote.

The group randomized pregnant women to receive either 800 mg of DHA daily or a placebo during the last half of pregnancy, and followed their offspring from birth through 7 years follow-up. They had previously been examined at 18 months of age and then again at age 4 years, with similar results.

Age 7 is "the earliest age where adult performance can be indicated," Gould and colleagues explained; 543 children (85% of original sample) were administered the full-scale IQ from the Wechsler Abbreviated Scale of Intelligence, Second Edition. The authors noted that there were higher numbers of preterm children in the control group, but that baseline data between groups did not differ significantly.

Parents were also asked to participate by completing standardized questionnaires about their child's behavior and executive functioning. The authors found that parents in the DHA group reported a significant difference in behavioral problems compared to controls (total difficulties score 9.71 versus 8.63, respectively, adjusted mean difference 1.09, 95% CI 0.18-2.00, P=0.02) and executive dysfunction (Global Executive composite 54.89 versus 52.54, respectively, adjusted mean difference 2.38, 95% CI 0.67-4.08, P=0.01).

Gould and colleagues noted these "small, but consistent" negative effects with behavioral problems and executive function were also observed when the children were followed up at 4 years of age, but said that while "they may reflect true effects, effect sizes were small and neurodevelopmental diagnoses did not differ between groups, they said.

Source: Medpage Today