These are the full videos you can view, however, I am giving you the times at which to view the specific clip because I cannot find them currently.
In the Hills Have Eyes 2, the mutant creatures kidnap women and rape them so that they can bear their young. Unfortunately, due to the fact that they have no idea how to reporduce, the mutants keep the women tied up, prolonged for the entire birth period, and when the babies are born (if that's what you can call them) they are more mutated and undead then ever before! Please view the portion of the movie I have linked below
Watch from very beginning till 2:36 in.The Hills Have Eyes: 2
In the Wrong Turn 2, the mutated inbreds don't kidnap women to breed, but they breed with eachother! In one scene I am posting, you see the birth of one of the mutated women who produce something so horrible it's hard to look at.
Watch from 00:36:24-00:38:02Wrong Turn 2
Like I said, these are horrific scenes that are not for the weak stomach. These are fictional but the portrayal of gruesum child births.