There is certainly a distinction between pro-choice and pro-abortion (demaguoguery).
In the first, a woman ultimately chooses the decision. She either gets an abortion or opts not to.
However, it's not the first time I've heard the logic - "What choice?" It's a choice of abortion, therefore, you support abortion.
So now, lets talk about pro-life and using the same thinking. If a woman is raped, and abortion is illegal, then some might say that you support the birth of the children of rapists. Some might even say "pro-rape".
I know, that perspective angers some, but lets continue with the "pro-life" semantics. If there is a medical condition that would endanger the life of the mother and essentially result in her death, how exactly does that make one 'pro-life'?
Some might say that's "pro-mother's death" (though that doesn't roll off the tongue so easily)
For many, decisions between a 'right and wrong', 'good or evil', seem simple and straightforward, but when asked to pick between two evils many have a difficult time of it even when using a highly theoretical and improbable example, they can't bring themselves to answer. For example:
You're in a hospital that's on fire, and know (in theory) that it'll explode in 8 seconds. You're the last adult evacuating and in the middle of a lengthy hallway at one end of the hallway (by the exit) sits a lost 2yr old child, crying, and will surely die, at the other end of the hallway is a lab with a container full of fertilized (frozen) eggs (by the other exit)
You only have time to save one. Which do you save and why? The child or the 100 eggs in vials?
The most common answer I hear, "that's so improbably that I won't even dignify the question with a response".
It's not meant to be a realistic scenario, it's theoretical and meant to identify the way we think about things.
Besides, it would probably be good for us to recognize that there really isn't such a thing as someone who is purely 'pro-life' or 'pro-choice'.
I doubt that most reasonable pro-choice people would support a woman to get an abortion a day before the actual birthdate, or support a woman getting 30, 40, 50 abortions, and other such circumstances.
I also doubt that most reasonable 'pro-life' people would support circumstances where the death of the mother would be a certain occurence, or a pregnancy due to a violent incenstual rape by the father of a mentally retarded 13yr old girl, etc.