Ewww!!! What movie is this from???

Question

I recently saw a compilation of horror movies clips, and was pretty much able to identify almost all of them, except for one; the clip had a young mother, sitting in a rocking chair, trying to get her newborn baby boy to suckle her breast. In failing to do so, the young woman exclaims, "I know what he really wants"; she then takes a knife, and cuts herself right above the nipple; bringing the baby once again to her breast, she sighs with ecstasy, when the baby suckles the blood from the freshly inflicted wound...

...what in the world was this from; it's sick, but I'm curious where it came from, anyways!!!

Answer 1

...you're talking about a clip from one of the strangest vampire films from the early-to-mid seventies, called "Grave of the Vampire"; the mother was a victim of rape by a vampire, and the baby was the unnatural offspring result of that attack. The baby grows up to be an obsessed and vengeful young man, partially inflicted with vampirism, and relentlessly on the search for the vampire who raped his mother...

Answer 2

I thought it was Rosemary's baby