Death is one of the consequences of terminating a pregnancy. Birth is another consequence. Abortion with death, and abortion resulting in a living baby are also both examples of terminating pregnancy. While there is a huge ick factor, I'm convinced that there is no rational argument to award a zygote, fetus, unborn child special rights that we do not award living, breathing babies, children, or adults. Bodily autonomy is an inalienable right that may, at times, result in the death of another person. As I said before, a viable fetus should not be intentionally killed during an abortion.
I know this is a tough argument to address without tremendous emotional baggage, but for me, when I look at the simple fact that we as a society fully understand that it would be WRONG to make someone donate a body part to save a life, it follows equally that someone who does not wish to continue being pregnant has that right, regardless of the outcome for the zygote, fetus, baby in the whom, whatever language you want to use. It's their body. The moral argument is powerful, but it has no play in this equation, only in the emotional space outside of the actual legal argument.