RE: for babies who can feel pain
At what stage in the womb has a baby been scientifically shown to feel pain?
I think the general consensus is after 20 weeks. Not that they did studies poking and hurting a fetus, but rather that they would poke at a woman's belly and see that the baby was reacting to the touch. It was assumed that if they baby could feel the touch, then they can also feel pain.
http://www.mccl.org/unborn-babies-can-feel-pain.html