The Terror Within (1989) (post apocalyptic)

In a post-apocalyptic world, 90% of the population is decimated by a plague. A group of survivors live in the Mojave Lab under the command of Hal, and every now and then, they need to get supplies from the outside world. When John and Michael leave the base, they lose contact and David, his dog Butch and Linda to look for their friends. They find them and a group of survivors of the plague slaughtered by a mutant called Gargoyle. Doctor Sue and Hal ask them to bring remains from one survivor to study how they survived the plague without vaccine, and Hal asks Andre and Neil to help him. However, David and Linda find one survivor alive, Karen, and bring her to the base. When Sue exams her, she finds that Karen is pregnant. Soon they learn that her baby is a mutant that escapes from the surgery room growing up rapidly and threatening their lives.