While pregnant you can eat clams as long as they are fully cooked, but it’s best to limit the amount. Raw shellfish are not recommended because they can contain parasites as well as bacteria and viruses that will cause food poisoning. During pregnancy, you are more susceptible to food poisoning, and parasites can make you ill and take away some of the nutrients you and your baby need. To be sure your clams are fully cooked the shells should open on their own. If the shells do not open, discard them.
Seafood is good for you, especially oily fish, but it also contains pollutants that need to be limited. While not an oily fish, clams are classified as seafood that contains moderate levels of mercury by the American Pregnancy Association, and ingesting high levels of mercury which can be harmful to you and your growing baby. The FDA recommends that pregnant women limit their intake of moderate mercury seafood to no more than six servings of six ounces in a month.
If you have concerns, consider taking a fish oil supplement instead of eating seafood, or consult your obstetrician.