I am passionately pro-choice, but that is because the issue is so complex that it can’t be easily resolved either way. That was the conclusion of Roe versus Wade: The science cannot settle the issue, therefore it is a religious not a scientific question, and therefore if the government outlaws abortion it violates the separation of Church and State. I taught a course on the ethical and metaphysical issues of abortion for several years, and almost every aspect of philosophy gets tied up with it. At the end of the course, most of my students concluded that they were anti-abortion and pro-choice. I even had one student who dropped out of college because she was pregnant and decided to keep and raise the Baby. However, she remained pro-choice because she felt her choice was so difficult that no one should be forced to make it.

The idea that life begins at conception seems preposterous to me, but it is possible if you accept dualism—the idea that the soul is a totally non-physical entity that can attach itself to pretty much anything. A lot of Christians believe that. The idea that a third trimester fetus is human seems far more likely than not, which is why Roe vs. Wade permits the banning of aborting such a fetus. Denying the right-to-life to a fetus just because of its location is not obviously justifiable without this thought experiment, and even then there are a lot of unresolved issues.

https://www.youtube.com/watch?v=c2PAajlHbnU&t=29s

Again, that why this must remain a matter of personal choice: Not because it’s simple but because it is too complicated for anyone to be sure what the right answer is.