You know, I have no idea. I was just trying to figure out a way to phrase things to be "neutral" about it, but I've never understood the "abortion" side of the argument.
I mean, I understand theoretically that if you simply don't believe humanity can exist while you are attached to the mother, then I guess abortion is just removing an unwanted growth -- but then why is there any angst at all, why make it rare, or be personally opposed? We wouldn't be personally opposed to removing a cyst, or want it to be rare that someone removed a cancerous growth when it was found.
So it's clear that most abortion supporters DO think there is something wrong with it, but a mother's rights trump whatever "wrong" there is. But if the only "wrong" that could possibly be is "humanity" of the unborn, then there is no way you could conclude that trivial matters of convenience trump the live of humanity.
So I just said "cause of abortion" to cover whatever argument one might think of that a pro-choice person might use, however odd or contradictory.