Actually, I think I have seen that happen, or at least it LOOKED like that was what happened -- although it is possible that they were already pregnant but just hadn't updated to show the baby (sometimes that takes a few moments to happen).

I have had something else happen that is very odd, as I've had my villagers gain healing skill when I drop them onto the dead bodies ... I've tried that one several times and can replicate the result (no dead villagers have returned to life, however, not yet, anyway