Here's a great video of Kathy Ireland explaining rationally why she switched from pro-choice to pro-life.
By the way, on the same YouTube page is a link to a video explaining why "abortion is not murder." Let me save you the time of watching that video. The argument begins (and ultimately falls apart) with the definition that a real human being must be able to survive on its own; i.e. outside of the womb. Who says? Why is survivability THE determining factor in our humanity? Are hospitals around the world filled with non-humans? Why is DNA not obviously the determining factor?
Do not fall for arguments that define humanity by survivability (or dependency), size, development, or other similar restrictions. Beware, because most of those arguments still apply to newborn infants and apply in part to toddlers and older children, as well as to the handicapped, diseased, elderly, and injured. Pretty soon you have no strong reason preventing you from killing the sick, the weak, and the undesirable.
It's been done before by "civilized" people. It's happening now. Some have no qualms about opening the door wider (perhaps they're confident they will never be classified as undesirable).