I'm against the death penalty in most cases, the UK has no death penalty, yet we don't have a tonne of mass murderers running about the place. I really don't think the threat of death is much of a factor when a murderer commits their crime, but i'm not 'pro-life'.
I think women deserve the right to choose what they do with their bodies, even if they choose to be the sluttiest bint in binttown. It doesn't affect those who are anti-abortion in the same way same-sex marriage doesn't affect people who are against it. Until that feotus has developed to a stage where it's basically just waiting to come out, it's just a bundle of cells. I agree, in the late stages of pregnancy at least, that abortion is probably not the best option (i say probably, because for medical reasons it might be) but until then, it's just an immensely difficult decision on whether or not to get rid of some biological material.