The Food and Drug Administration and Environmental Protection Agency's proposed guidelines suggest that pregnant women or women who are nursing eat between eight and 12 ounces of low-mercury seafood a week, according to the NY Daily News.

Consumer Reports is reportedly warning that pregnant women should exclude tuna from their diet altogether.

"Consumer Reports disagrees with the recommendations from the FDA and EPA on how much tuna women and children may eat. We don't think pregnant women should eat any," the group stated in a report.

According to the FDA and EPA, eating fish, including shellfish, has been found to have a number of health benefits.

However, Consumer Reports and other researchers have reportedly found that some seafood contains high levels of a form of mercury called methylmercury, according to NBC San Diego.

"Mercury can damage the brain and it can damage the nervous system, especially when that exposure occurs in the womb," stated Dr. Michael Crupain with Consumer Reports.

Crupain added, "Children and anyone who eats a lot of fish should really limit the amount of tuna they eat."

Consumer Reports has analyzed the FDA data and picked out 20 fish "that can be eaten several times per week, even by pregnant women and young children, without worrying about mercury exposure."

Despite Consumer Reports' suggestion for pregnant women to cut tuna out of their diets, agencies reportedly stress that fear of mercury is not a reason to completely cut out fish.

"Avoiding fish during pregnancy in favor of omega-3 supplements means that you would be missing out on many other important nutrients contained in fish that are required for overall health," the guidelines read.