"Killer Baby" movies are a popular monster/horror subgenre for an obvious reason: It's the ultimate extreme of both the "deceptively-harmless-looking-killer" conceit and the "evil-perversion-of-goodness" conceit. We're biologically/evolutionarily hardwired to respond viscerally to babies - that jolting chill up your spine when a baby cries somewhere? That's your ancient, ancient instinct telling you "YOUNG ONES IN PERIL! PROTECT THE FUTURE OF THE PACK!" - and Killer Baby movies exploit that.
The best one is still Larry Cohen's seminal "It's Alive" (the original, Cohen's own well-meaning remake kinda sucks) but there've been plenty since. To my recollection, though, Tara Robinson's upcoming "After Birth" is either the first or the first in a long time to come from a female filmmaker. In this variation, a homeless woman is impregnated by an evil force and must confront the killer creature she gives birth to. If nothing else, it has TWO of the best ad-copy lines I expect to see this year...
"Every Child Is A Gift From God... EXCEPT ONE!"
"For One Girl... Pro-Life... Is A DEATH SENTENCE!"
THAT, friends, is how you sell me a Killer Baby Movie. Keeping an eye on this one.