Toddlers whose mothers took fish oil supplements during pregnancy tended to have better hand-eye coordination than children whose mothers didn't take the supplements, a new study found.

The results of the small study by Australian researchers appear online in the Dec. 21 issue of the Archives of Disease in Childhood.

"Omega-3 fatty acids, commonly referred to as 'fish oil,' are essential nutrients for human health," said Dr. David L. Katz, director of the Prevention Research Center at Yale University School of Medicine. He was not involved in the study.

"Along with essential omega-6 fats, these compounds influence everything from hormonal balance to immune function," Katz said. "Omega-3s are taken up avidly by the developing eyes and brain of a fetus, and are thought to be important contributors to healthy development in early childhood."

Because of concerns about mercury in certain types of fish, fish oil supplements are becoming more popular, the study authors noted.

In the study, by researchers at the University of Western Australia's School of Paediatrics and Child Health, 98 pregnant women were given either 4 grams of fish oil supplements or 4 grams of olive oil supplements each day starting at 20 weeks of pregnancy until their babies were born.

When the children were two-and-a half years old, their growth and development was tested. The tests included tests for language, behavior, practical reasoning and hand-eye coordination.

Among the 72 children tested, the researchers found no significant differences in language skills and growth between children whose mothers had taken the fish oil supplements and those whose mothers hadn't, the researchers found.

However, children whose mothers had taken fish oil supplements scored significantly higher in hand-eye coordination, compared with children whose mothers had not taken the supplements. This association held true even after the researchers accounted for the mothers' age and length of time they breast-fed.

In addition, the researchers found that high levels of omega-3 fatty acids in the babies' umbilical cord blood were significantly linked with good hand-eye coordination, while low levels of omega-6 fatty acids, found in many vegetable oils, were not.

"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," the authors wrote. "Given the scarcity of data to support the efficacy of fish oil supplementation during pregnancy, our data have a potentially important role in informing on the effects of fish oil supplementation on early postnatal infant development," they concluded.

Katz said: "This study confirms that supplements of fish oil taken by pregnant women can influence the hand-eye coordination of their offspring. Whether that translates into long-term benefits in vision, coordination, or cognition remains to be seen. But the findings certainly hint at the importance of omega-3s to the health of young children."

It will take more research to clarify the optimal dose of omega-3 fatty acids, and the long-term health effects of supplementation during pregnancy, Katz said. "But we know enough already to conclude that fish oil from supplements is generally a good idea, during pregnancy especially. I routinely advise 1 gram, twice daily, of fish oil to my pregnant patients -- and my non-pregnant patients, too."