There is no other ethical dilemma that can quite be compared to pregnancy and abortion. It is even a legally murky area. Abortion is legal, yet if you kill a pregnant woman you can be charged for two murders. Is it okay to kill a life as long as it is symbiotic and can't survive outside of the womb? However, no baby can survive out of the womb without adult care anyway. Then you have further debates as to when abortion is okay or not okay- and what makes a person a person in the first place. Is it when someone has their full capacity to reason? If so, is a child not legally a person? Then there is the whole addition of rape, incest, and the mother's life being in danger to complicate things. There's all sorts of murky areas to this.
It's life, but it is symbiotic life. It is life that has the potential for becoming human. I believe that once a certain stage of development passes, it is undoubtedly murder. Viewed in this context- rape, incest, and the mother's life being endangered seem to be the most reasonable parameters- as while abortion is never ideal, it can be used if necessary.
That said, I do hold double standards when it comes to abortion. I think life is sacred, and would personally only have an abortion if my life was in danger, and it was recommended to me by my doctor (and even then I'd get a second opinion, talk to my priest and husband, and engage in some serious prayer before making the decision). If I were raped and became pregnant, I would keep the child. I also have the expectation that no Christian would choose abortion unless there were extremely serious issues to consider (and deciding you just don't want a child after choosing to have sex isn't one of these serious concerns), as their views on the sanctity of life should also exist.
I just can't see holding non-believers and/or people not of my faith to the same standards to which I hold myself and I don't think I should be the one calling the shots for others. This is why I view abortion as a necessary evil, and wish there was more education out there to discourage it, educate people on preventing (when possible) unplanned pregnancies so they don't have a difficult choice to make, and provide more services to help and support women and mothers, et cetera. I think women who've had abortions experience difficulties (even if brought on by their own actions), and need our compassion, not our demonization so they can heal. Even though I don't hold others to my standards, I think other people should never see abortion as a good thing.
I absolutely think there should be a focus on teaching responsibility before it ever gets to the point of someone even considering abortion as an option. It's not an ideal option and should be viewed accordingly. If some are using abortion as their only means of birth control, then they need an intervention, in my opinion.