I don't think that we'll be seeing much of Christa and Omid again until season 3, although in another post I did say that I think we will run into someone who's seen them. A pregnant woman and little girl would stick out in people's memories during a crisis, especially when meeting other live people is already a rarity.
I expect that things will work out for them. Christa is sort of a ball buster, but she's tough and resourceful. People who have those traits tend to do well, whatever the situation. And, as some others have said, Omid seems pretty lucky. It's hard to picture him just dropping dead one day. (Though, of course, we all will eventually.)
The whole zombie baby thing has already been done a few times now (not by TTG, but by others), so I would be really surprised if she had a dead/zombie baby. I imagine that the child will live. How long is up for debate, but I think she will deliver their baby successfully and that it will be alive and well at least long enough for us to meet it.