It is in the news almost daily: Eating fish several times a week is a healthy habit. Pregnant women, however, have to be attentive to avoid certain types of fish that have higher levels of mercury, which can be harmful to the development of the brain and nervous system of a fetus
The Food and Drug Administration (FDA) recommends that children and women who are pregnant or trying to get pregnant should eat more than 12 oz. (Two average meals) of low-mercury fish per week. These include anchovies, calamari, king crab, pollock, catfish, scallops, flounder, haddock, lobster, crayfish, salmon, shrimp, clams, tilapia, oysters, sardines, sturgeon and freshwater trout.
The FDA recommends that pregnant women eat no more than 18 oz. high mercury fish per month. High-mercury fish (not to be confused with the highest mercury fish, below) include saltwater bass, croaker, halibut, canned, white albacore tuna, bluefin tuna or AHI, sea trout, bluefish and American or Maine lobster.
Since these fish carry the highest levels of mercury, the FDA recommends strongly that pregnant women abstain from eating them throughout pregnancy and while breastfeeding, grouper, marlin, orange roughy, tilefish, swordfish, shark and king mackerel. Of these, tilefish, swordfish, shark and king mackerel have the highest levels.
Levels of mercury vary in tuna, depending on the type tuna and how it was captured. The Natural Resources Defense Council developed a chart that helps pregnant women, women trying to become pregnant, and children determine how much canned tuna is safe to eat. (See Resources.)
Fish caught in local lakes, rivers or coastal areas must be considered for their mercury levels too. Check with local guides about the safety of eating fish caught locally. If no information is available, use up to 6 oz. per week, but do not eat other fish that week.