Nearly all fish contain some low levels of mercury, but also provide healthy nutrients. Fish with low mercury levels should be limited to 8-12 ounces per week and include: Pollack, Shrimp, Catfish, Salmon, Canned Tuna (Albacore is higher in mercury than light Tuna) and all fresh water fish. Fish with high mercury levels which should be avoided include: Swordfish, Tilefish, King Mackerel and Shark.
If you have a specific concern, take a look at the FDA’s website regarding eating fish in pregnancy. www.fda.gov/food/consumers/advice-about-eating-fish