Researchers from the University of Western Australia recruited 98 pregnant women who did not smoke and ate fish no more than twice per week. The researchers gave one group of women 4g of daily fish oil supplements starting at 20 weeks of pregnancy, while the second group was given daily 4g supplements of olive oil from 20 weeks on.
When the women's children were 2.5 years old, the researchers administered growth and development tests. The children of the women who had taken fish oil supplements scored much higher in hand-eye coordination, comprehension, phrase length and vocabulary than the children of the women who had taken olive oil supplements.
The researchers accounted for factors such as breastfeeding and the mother's age, and still found that the children of mothers who'd taken fish oil were more advanced in development, coordination and brainpower.
"These preliminary data indicate that supplementation with a relatively high-dose fish oil during the last 20 weeks of pregnancy is not only safe but also seems to have potential beneficial effects that need to be explored further," said study leader Professor Susan Prescott.
The researchers believe that the last three months of pregnancy are a vital time for pregnant women to take fish oil supplements, since the baby's brain experiences a growth spurt during that time, which lasts through the first few months of the infant's life.
The high omega-3 fatty acid content in the fish oil plays an important part in proper development of the child's central nervous system. Previous studies have shown that omega-3s can also benefit the mother during and after pregnancy by lowering high blood pressure and relieving postpartum depression.