A pregnant woman can eat shellfish safely, according to Mayo Clinic, as long as she eats it in moderation. The mercury in seafood is why pregnant women should limit shellfish. The U.S. Food and Drug Administration notes that a pregnant woman can consume up to 12 ounces of shrimp weekly.
Pregnant women who opt to consume shellfish, including crab and shrimp, should ensure the seafood is cooked thoroughly. Mayo Clinic recommends that pregnant women avoid seafood that is refrigerated but uncooked, such as lox. An exception noted is if the shellfish or seafood is consumed in a dish that is cooked.