Rosemary's Baby is the title of a horror novel by Ira Levin, in which a young religious woman and her husband move into a New York City apartment next door to enthusiastic, oversolicitous neighbors. The couple want to have a baby; one night the woman has a vision that she is being raped by some demonic presence and later she finds out that she is pregnant. The woman begins to lose weight instead of gaining it, and comes to suspect that her neighbors are part of a Satanists' cult, and that her husband is working with them.
The novel was adapted to film by Roman Polanski and featured Mia Farrow as the wife, John Cassavettes as the husband, and Ruth Gordon and Sidney Blackmer as the oversolicitous neighbors. Gordon won an Academy Award for Best Supporting Actress for her work in the film.