You don't understand the difference though - of how little these babies can cognite. Children can cognite, retards can cognite, too (though in a different way than how we percieve).
I have to say that I don't think there is a lot of justification in killing any human life, no matter what stage the life form is in.
Basically, what will pain you more to see: An abortion or killing a baby? An abortion is aborting what will eventually develop into a human life, a killing is killing a human life.