Eating lots of fish in pregnancy linked to obesity risk for kids

PREGNANT women who eat more than three servings of fish a week – that is, more than the maximum recommended by US health regulators – may face an increased risk of having babies who grow rapidly and become obese in childhood, a research review suggests.

Previous research has linked one pollutant in fish – mercury – to damage of the nervous, digestive and immune systems, lungs, kidneys, skin, and eyes. Because of this, the US Food and Drug Administration and Environmental Protection Agency encourage pregnant women to limit consumption to no more than three servings a week.

The current study points to another risk for pregnant women to consider – the potential for pollutants in fish to contribute to childhood obesity by interfering with hormone system development while babies are in the womb, researchers report in JAMA Pediatrics.

Women shouldn’t avoid fish altogether, because it’s a rich source of important nutrients like protein, vitamin D, and omega-3 fatty acids – but they shouldn’t overindulge, said lead study author Dr. Leda Chatzi of the University of Crete in Greece.

“Our findings indicate that women should adhere to current fish consumption guidelines,” Chatzi said by email.

“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,” Chatzi added, identifying some varieties that may contain more pollutants.

To assess the connection between maternal fish consumption and childhood obesity, Chatzi and colleagues analyzed data from 15 previously published studies that tracked more than 26,000 pregnant women and their children at two-year intervals until the kids reached age six.