Raw seafood is sometimes seen as a delicacy. Sushi and oysters on the half-shell are just two examples. These foods are not safe to be consumed at any time, but especially during pregnancy. The immune system of a pregnant woman is altered somewhat and she is more susceptible to illnesses that can be caused by organism present in raw seafood. Two especially dangerous diseases commonly associated with seafood are cholera (caused by Vibrio cholera) and hepatites (caused from a virus).om a