In June, the government put out new recommendations telling Americans to eat more fish because of the health benefits. The Food and Drug Administration recommends pregnant women eat up to 12 ounces of fish per week which can include some small amounts of canned tuna.
But Consumer Reports did its own analysis and is telling pregnant women to avoid tuna completely. The magazine says the problem is that mercury levels in canned tuna can vary, so you don't know what you're getting. The FDA says most canned tuna is safe , but the agency's own research found 20 percent of cans tested actually had high levels of mercury.
Still, the FDA is holding by its recommendations and told CBS News:
"The Consumer Reports analysis is limited in that it focuses exclusively on the mercury levels in fish without considering the known positive nutritional benefits attributed to fish."
Consumer Reports says there are plenty of fish besides tuna that are better options for pregnant women.
Low mercury fish include wild salmon, shrimp, sardines, tilapia and scallops. The group believes these fish can give pregnant women the health benefits without the risk.
Some health experts say chunk light canned tuna has less mercury than albacore canned tuna.