I'm looking for a book that I read in highschool that was not pg friendly and had gore in the literature.

So I read a book about a dad taking his daughter to a doctor and they chat a bit mostly normal it seem than baby pop out not in normal way but messy bloody that kills the daughter. The nurse got hurt and look like she dead. The dad was killed as well by the baby after the demonic baby spoke to him. As more people I assume show up someone had a gun and fire at it. They also died and doctor who is thinking is only one alive took the gun and shot himself believing he allow whatever it was (which was a demon) to live. I'm trying to remember what the title is so I can buy the book.