First, there is no scripture in the Bible which directly relates to abortion. Just like many other issues, we are left to make the best decision possible. Therefore, from a Christian perspective, there is no slam dunk right or wrong.
However, I was raised anti-abortion. I accepted that view for a long time. Finally, after I questioned that view and studied the scripture, I changed my opinion.
For me, it was Exodus 21:22 which states, "If men fight, and hurt a woman with child, so that she gives birth prematurely, yet no harm follows, he shall surely be punished accordingly as the woman's husband imposes on him; and he shall pay as the judges determine. But if any harm follows, then you shall give life for life, eye for eye, tooth for tooth, hand for hand, foot for foot, burn for burn, wound for wound, stripe for stripe."
According to the majority of scholars (I believe), this verse means that if the woman miscarriages, then he will be fined, but if the woman dies, then he shall be put to death. To me, the reason this scripture is important is that it shows a difference between fetal life and human life.
I do not mean to offend anyone with different views. The subject of abortion is very touchy. However, I believe that Casey was a pretty good decision. Anyway, I don't believe that the life of a baby from rape, incest, etc. is any less precious. Therefore, I don't buy the "no abortions with exceptions" idea.
Just my opinion and how I arrived there.