According to Livestrong, mushrooms are a safe choice during pregnancy. However, it is essential that pregnant women wash their mushorooms prior to eating them. Unwashed produce may contain harmful bacteria and parasites that can cause food-borne diseases such as toxoplasmosis and listeriosis according to the FDA and the American Pregnancy Association.
Some mushrooms are poisonous. Pregnant women should make sure they are buying mushrooms from a safe provider.