If canned immediately after smoking, it should be fine.
Besides the heavy-metal contamination issue, make sure that the friend who smoked the fish knows what he is doing regarding smoking it completely, i.e., not leaving it raw in the middle and then failing to refrigerate it. Raw fresh fish is not unhealthy (absent the heavy-metal issue), but raw fish that has sat out for days in the cupboard because someone thought it was completely smoked is not anything I'd eat, preggers or not.
Another reason I'm proud to be from Alaska. :) there is a post in here a few pages back. I think the subject is :email a friend sent me. There is a bunch of myths and facts on such things as fish and sushi.
It depends on where the salmon came from. Wild-caught Alaskan salmon is usually considered healthy and free of heavy-metal contamination, but Atlantic salmon is not.