I think to phase it more specifically, the question is if a fetus's right to live and develop overrides a woman's right to determine how her uterus and other organ systems will be used. And if so, when in pregnancy does the mother's bodily autonomy become subordinate to the fetus's right to life?
To me, the big problem is that most people envision only two anwers--which are the two extremes. 1) A fetus has no rights until it's born. 2) The fetus's right to life supercedes the mother's bodily autonomy from the moment of conception (a life-threatening maternal illness excepted.) Why can't people accept a middle position? What's wrong with picking some point between conception and birth--like when a fetus is natually viable (24 weeks)--and saying that before 24 weeks, the mother's bodily autonomy overrides the rights of a fetus. After 24 weeks, the fetus's right to be born takes precedence. If the laws would reflect this view, it would allow elective terminations of viable, 3rd trimester fetuses to be restricted, yet still provide plenty of time for a pregnant woman to make a private decision regarding her reproductive options. Sure, it's arbitrary, but our laws make arbitrary distinctions all the time. Even with life and death matters. (Example: if I commit first degree murder here in Missouri, I could be executed. But if I commit exactly the same crime in Iowa, just over our northern border, my life will be spared.)
Why does abortion have to be all or none? What's wrong with a compromise?