Sorry, Pregnant Women, New Study Is Not a Carte Blanche to Eat Sushi

— -- Despite jubilant tweets and Facebook posts to the contrary, a new study does not reverse decades of advice prohibiting pregnant women from eating sushi, experts said.

The study published in the American Journal of Clinical Nutrition said pregnant women may be able to eat more fish than previously thought thanks to what appear to be minimal negative effects from mercury consumption on their unborn children, but experts say sushi is a whole different story.

Researchers at Rochester University followed more than 1,200 pregnant mothers in the Republic of Seychelles until their children were 20 months old. Seychelles is an archipelago in the Indian Ocean where people eat more fish than they do in the United States.

"They don't really eat sushi," said study author Gary Myers. "That's the first thing I would say. They ate quite a wide mixture of fish -- much wider than what we have in the states, actually."

The pregnant women in the study ate 12 fish meals a week on average, and researchers concluded that the fatty acids found in the fish may have protected children's brains from the harmful effects of mercury. Researchers found that pregnant women whose blood had higher levels of the polyunsaturated fatty acid found in fish went on to have children who performed better on a battery of tests on motor skills and other functions that might be effected by high mercury levels.

The U.S. Food and Drug Administration recommends that women eat no more than 12 ounces of fish or two fish meals a week, but Myers said it's considering whether to allow more.

For now, Dr. Jeff Ecker, who chairs the American College of Obstetricians and Gynecologists' Committee on Obstetric Practice, said women should continue to follow the current FDA recommendations. He said the study might help convince the FDA to change the guidelines, but more research analysis is needed.

"The study suggests, as has been known for a while, that there are real benefits from fish eating," he said. "The balance between the benefits and potential risk of mercury exposure and this work suggest that there's not as direct a relationship between mercury exposure and adverse outcome as initially thought."

Still, pregnant women are told not to eat raw or under-cooked fish for several reasons, said teratologist Robert Felix, who studies and counsels women on how things during pregnancy effect their unborn children. If it is not prepared and handled properly, sushi can cause parasitic infections, be cross-contaminated by bacteria or other substances or contain high levels of mercury, Felix said.

The U.S. Centers for Disease Control and Prevention recommend that pregnant women only eat fish cooked to at least 145 degrees Fahrenheit.