Seafood is a lean protein that has always been considered a healthy alternative to fatty meats and poultry. It is also rich in the omega-3 fatty acids that are important for a growing baby's brain development.

However, many species of fish have become so contaminated with chemicals and heavy metals that they are no longer safe to eat, especially for pregnant women. The EPA estimates that 630,000 babies are born in this country each year with high levels of mercury — a condition that can lead to neurological, developmental, and cognitive problems for your baby down the road. But fear of mercury doesn't mean you need to eliminate all seafood from your diet. Just be very cautious about the types and quantity of seafood that you eat.

Safer Seafood

The FDA and EPA currently recommend that pregnant women avoid eating shark, swordfish, king mackerel, and tilefish as these fish are known to contain high levels of polychlorinated biphenyls (PCBs) and mercury, two contaminants that are particularly harmful to a developing fetus. Many OB/GYNs and midwives also suggest that expectant moms limit their consumption of tuna, oysters, salmon, marlin, halibut, and sea bass.

Wild or Farmed?

Choose wild-caught fish over farmed varieties whenever possible. Farm-raised fish are often raised in tanks or net enclosures that are stressful for the fish and may facilitate the spread of disease and contamination. Farm-raised fish also tend to contain significantly higher concentrations of PCBs, dioxin, and other contaminants.

You should also avoid eating refrigerated, smoked seafood labeled lox, nova style, kippered, or jerky that has not been cooked, as these may be contaminated with Listeria. And avoid fish caught locally from contaminated lakes and rivers. Contact your local health department to find out which fish are safe to eat in your area.

Wild-caught fish, on the other hand, are harvested directly from their natural habitat. Depending upon the species of fish, they may have a lower risk of disease and contamination than farm-raised varieties.

According to the Marine Stewardship Council, an independent agency that certifies the sustainability of various fishing industries, the following fish species are the most likely to have been harvested sustainably:

WILD-CAUGHT FISH

• Anchovies

• Atlantic herring

• Atlantic mackerel

• Crab (blue, Dungeness, snow, and stone)

• Flounder

• Herring

• Mahi Mahi

• Salmon

• Scallops (bay)

• Sardines

• Shrimp (northern, Oregon, and spot)

FARM-RAISED FISH

• Abalone

• Catfish

• Caviar

• Clams

• Mussels

• Oysters

• Scallops (both sea and bay)

• Striped Bass

• Sturgeon

• Trout

The FDA recommends that pregnant women can safely eat about 12 ounces of cooked fish each week. Use this list as you guide to finding fish that have been harvested with concern for the environment and talk to your health care provider about the risks and benefits of eating seafood while pregnant.