That depends on the circumstances which would have led to me being born to an orphanage. If somebody is going around creating people willy-nilly out of genetic material they found lying around, uh, no, please stop them, I'd be okay with not having been born. If I'm an accident and happened to have a pro-life mother in this hypothetical... well, the emphasis in pro-choice is "choice", so in that case it depends whether someone would swoop in and prevent my birth against her will or whether she would change her mind. In the latter case, the abortion doctor has my blessing. In the former case, (s)he hasn't, but only because I don't think medically elective surgery should be performed on unwilling patients, not because I think the lives of accidental fetuses are particularly valuable. If I was conceived by a stable, loving, child-wanting couple and my hypothetical dad was hit by a bus during my gestation and my mom died in childbirth, then I'd be okay with being born as opposed to not being born.