Godforbid we are just told to eat something good for us. No, it's never that easy. Can you scream omega fatty acid and mercury at the same time?
Here's what I gathered: fish is good for you because it contains omega fatty acids that can reduce the risk of heart failure and stroke, plus it can help brain development in the baby. Yay! But wait! Fish can also be high in mercury which can cause problems with cognitive development in unborn children. Boo! Although, theoretically, if both were true, wouldn't we all have average kids because the omega acid would cancel out the mercury? Guess not.
Anyway, it looks like large fish are the mercury culprits and small fish are good to eat. In short:
Bad: albacore (white) tuna, swordfish, shark, tilefish (golden bass or golden snapper), king mackerel
Good: pretty much everything else including skipjack (light) tuna
search: fish and pregnancy, consuming fish while pregnant, safe fish for eating