Study: DHA supplements may help premature baby girls

Australian doctors tested the fatty acid, DHA, in premature babies to see if it reduces the rate of mental retardation, which is more common in babies born very early, according to a study in today's Journal of the American Medical Association.

Doctors focused on 657 babies born before 33 weeks — about seven weeks before the end of the average 40-week pregnancy. Doctors randomly assigned half of newborns to a high-DHA diet and half to a standard one. For the high-DHA diet, breastfeeding mothers took six 500-milligram tuna fish oil capsules and, if needed, babies received infant formula in which DHA made up 1% of the total fatty acids. Mothers of babies on the standard diet got placebo pills, and their babies got regular formula.

Babies underwent standard development tests at 18 months.

Doctors found no difference in mental retardation rates overall or in boys, the study shows.

But premature girls given the high-DHA diet scored about 5 points higher on a 100-point test, which translates to a 55% reduction in the proportion of girls with a "mild mental delay" and an 80% reduction in the proportion of girls with "significant" mental delay, says author Maria Makrides of Women's and Children' Hospital in Adelaide, Australia. She notes that premature girls generally have lower risks of complications than boys.

There were no harmful side effects of taking DHA, which mothers naturally pass on to their babies in the womb. Babies born early miss out on the benefits of DHA, which may help develop their brains during the critical last weeks of pregnancy, Makrides says. She notes that the preemie girls given extra DHA had test scores nearly as high as those of full-term babies.

Based on those findings, her hospital is preparing to offer a DHA-rich diet to its preemies, Makrides says.