Contrary to some recent news reports, the U.S. Food and Drug Administration (FDA) has not issued a new advisory on methylmercury consumption. FDA's current advisory regarding methylmercury and fish consumption still stands.
The current advisory, issued March 2001 http://vm.cfsan.fda.gov/~dms/admehg.html recommends that pregnant women and women of childbearing age who may become pregnant not eat shark, swordfish, king mackerel, and tilefish. Also, as prudent public health advice, FDA also recommends that nursing mothers and young children not eat these four varieties of fish because of the relatively high levels of methylmercury they may contain.
The current advisory acknowledges that seafood can be an important part of a balanced diet for pregnant women and women of childbearing age who may become pregnant. Further, the current advisory provides that pregnant women and women of childbearing age can safely eat 12 ounces per week of a variety of other kinds of cooked fish (typical serving size of fish is from 3 to 6 ounces).
FDA believes that women following FDA's advisory would generally be below the Environmental Protection Agency's (EPA) reference dose for methylmercury. FDA received a number of recommendations from its Food Advisory Committee last summer on how to improve this advisory. FDA will continue to work closely with EPA and others in developing the best science-based approaches to dealing with methyl mercury in fish.
Source : U.S. Food and Drug Adminstration - www.fda.gov