Why am I pro-choice in the USA : Because outlawing abortion is the alternative which leads to :
1) Females being seen by society as nothing more then incubators that can simply be raped when males would like a child if females don't have the option to abort a product of rape.
2) An explosive increase in the number of unwanted children forced into an already over-loaded foster care system that lacks proper resources to take care of existing unwanted children.
3) An explosive increase in illegal abortions, including ones that potentially endanger the life of the mother and ones that are particularly inhumane, because of the desperation of females who were raped, don't feel ready to be a mother or coerced by others to abort.
4) An explosive increase in birth defects (a pregnant female who is compelled only by law and not by her own will to give birth is almost certainly not going to take the proper steps necessary to ensure a healthy child).
5) An explosive increase in the number of single/extremely young mothers which in turn leads to higher rates of death (pregnant female is so young she can't bear the pregnancy), suicide, crime, welfare dependency, aggressive tendencies in their children, child abuse of unwanted children, etc.
6) An explosive increase in the number of false rape accusations, particularly if rape cases are exempt and treated as exceptional cases where abortion is allowed.
7) An explosive increase in poor pregnant females dying from complications because they couldn't afford healthcare during pregnancy.
I'm against these negative consequences on society more than I'm against early-term abortion. As a result, I'm against criminalizing abortion. I'm totally in favor of encouraging people to be smarter about who they sleep with and how, including making it easier for us to adopt children born from females unwilling or incapable of raising them. That's very different from having our government force females at gunpoint who are unwilling/incapable of bearing a child to have the child anyway.
The ideal scenario pro-lifers seem to imagine is this utopia where children are running around happy, where some baby who might have formerly been considered for abortion finds a cure for cancer or something like that. The reality is that criminalizing abortion is simply forcing a large number of females to bear a child regardless if any of the above circumstances are in play. If I genuinely believed it was a recipe for happy and productive lives, I'd be pro-life, but reality strongly suggests that it's a recipe for human suffering, for the females forced to give birth and the unwanted children and the society that must witness and bear the burden of this.