There's something quite human involved here. I have a stick downstairs I picked up on a shoreline last month. It's a fine stick, long enough to become a walking stick and shaped in interesting ways by the waves. I plan to sand it a bit, varnish it and make a staff out of it. I value it and would be irritated if you threw it out. But it's just a stick.
I accept that I pull out some things from the world and value them more than others. Some things get a kind of status beyond their physical attributes or the arrangement of their molecules. I also seem to have no trouble ranking these things, thinking my stick worthwhile, but not as worthwhile as, say, my Internet connection. Should I be forced to choose, I can easily pick one over the other.
In any case, there's a method to cut through the crap when it comes to abortion. Here's what I do. Since I cannot evaluate the situation without being in the situation, my default is to ask the mother. So long as she is sane and has some minimal facts, it's up to her to decide. It's her value system and ranking that matters, not mine.
So I dodge the absolutes here. It's the only way forward as far as I can tell. Use one set of ungraspables (when life begins) set against another (how a mother evaluates carrying her fetus to term). The only thing left, from a societal point of view, is to make sure her decision isn't subtly driven by circumstance society/culture creates. She has to have room to maneuver.
This puts me in the pro-choice camp, but with one caveat. She should be making an informed, serious decision, with actual options available and the least amount of pressure possible.
It also makes me a moral coward. I can't be brave enough to come up with a firm moral position, so I'm passing the buck to the woman concerned. I'm going with pragmatic and taking the coward's way out.