Prometheus Rating
Think Progress’ Alyssa Rosenberg learned that Prometheus got an R rating because of a scene in which Noomi Rapace’s character surgically removes an alien fetus from her womb. So the MPAA took issue with a woman trying to remove a vicious, predatory creature from her that would have killed her if she hadn’t, but was ok with all the other grotesque imagery in the film?
(For more evidence that MPAA ratings are based in twisted morals, check out this A.V. Club article.)