This movie has them all beat, I made the mistake of renting it because it sounded like a cheesy teen horror flick. It looks like it was made back in the 70's and the worst I have ever seen. It's called, "The Suckling" and for those who have never seen it, prepare.
The movie starts off as phyciatrists are discussing an odd event involving a murder and a female survivor where she is there being treated. It then goes back to when she was younger and joins her boyfriend as they visit a abortion/whore house to discuss their options. That alone made me rent it. Once there, "Big Momma" as she is called performs the abortion and they flush the fetus down the toilet. In the drains, Toxic waste mixes with the fetus and forms "The Suckling". One by one the whores and the johns die by this mutant killing baby with it's teeth, claws, and umbilical cord, not sure of the correct spelling. In the end, The baby returns to the mother sparing her life as he returns to the womb ready to be reborn again as you will see in the end.
I'd like to see any other movie top this one.