My midwife asks me if I'm eating fish because of the good nutrients it provides in my diet and implies that I really should be eating more (because I don't eat much fish at all. Fresh, well cooked fish is important.

I think it is wise to stay away from seafood that has been stored after cooking (e.g. prawns) and the bigger fish varieties that might contain high levels of mercury. Maybe ask another midwife to clarify the seafood/fish issues for you