With "kid scenes", it totally depends on the way it's done.
I can laugh at the "playground zombie baby beating scene" in "Braindead" (though I laughed certainly louder when I still wasn't a dad!), but the scene in "Murder Set Pieces" when a screaming real life 18 months old baby gets shouted at by the killer and has to face the sight of a mutilated woman is simply unacceptable. Babies can't "act", so involving them in such a grim scenario is something a remotely respectable filmmaker should clearly avoid!
