Many types of fish products should be avoided altogether during pregnancy and while nursing. Due to potentially high mercury content, avoid eating swordfish, shark, king mackerel and tilefish. Also, lake fish should be avoided altogether, due to the risk of chemical/pesticide contamination. Raw or partially-cooked shellfish should be avoided due to the risk of bacterial contamination.

However, certain types of seafood are safe to eat. Some very-low mercury alternatives include shrimp, pickerel, whiting, salmon, tilapia, sardines, catfish, flounder and sole. We recommend no more than 12 ounces per week of these products, however.

Because the data on mercury content in albacore (white) tuna is unclear, we recommend no more than 3 ounces per week. Or better: choose chunk light tuna, which has far less mercury than albacore.