Yet another study looks at the effect on a developing baby of moms eating fish during pregnancy, with a surprising conclusion.
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For years, doctors counseled pregnant women to avoid eating too much fish due to concerns over mercury's impact on baby's developing nervous system. Then recently, a study came out linking the consumption of fatty varieties, like tuna, during pregnancy to higher cognition in kids. And another went so far as to break down the why. Now, yet another study has been published, and let's just say it muddies the waters even further.

The Greek study, which appears in JAMA Pediatrics, found pregnant women who ate fish more than three times per week saw an increased risk of having babies who grow rapidly and then become obese in childhood. That's because pollutants from the water can interfere with the hormone system development of the fetus, researchers say.

To reach their conclusions, the researchers looked at a composite of 15 previously published studies including more than 26,000 pregnant women and their kids over the course of 15 years. The children, who were born in various European countries and Massachusetts, were analyzed at two-year intervals until they reached the age of 6.

Moderate fish intake of three times per week or less showed no correlation to rapid growth or obesity. But researchers noted women who ate seafood more frequently had a 22 percent increased risk of seeing this effect. Interestingly, it seemed to be more pronounced in girls versus boys. Could this have something to do with their hormonal differences? Researchers did not say.

Lead study author Dr. Leda Chatzi, assistant professor of nutritional epidemiology at the University of Crete in Greece, did recommend adhering to the current U.S. Food and Drug Administration and Environmental Protection Agency recommendation that pregnant women eat three servings of fish per week, adding, "In general, women should eat a variety of types of fish each week and avoid consumption of large predatory fish such as king mackerel, swordfish, shark, and tilefish." Larger fishes will contain more pollutants, and therefore should not be eaten often during pregnancy.

It's worth noting this study cannot definitely say eating more seafood causes childhood obesity; it's merely an association. The study may also have simply picked up on a link between women eating more in general and having an obese child. Further, it's important to point out that fish consumption still offers benefits to pregnant women, namely the brain-boosting abilities of omega-3 fatty acids, which oddly, have been found to fight obesity in other studies.

The takeaway: Everything in moderation.

What's your take on this latest study?

Melissa Willets is a writer/blogger and a mom. Follow her on Twitter (@Spitupnsuburbs), where she chronicles her love of exercising and drinking coffee, but never simultaneously.