It doesn't matter when life begins. It matters when humanity begins. I think the vast majority of people have no problem with killing things in general (like fish and carrots) but take offense to killing humans. I have done a fair amount of research to address this since I prefer to make informed decisions. In terms of typical abortion vernacular, the lumps of cells that have potential to eventually turn into a human actually begin to have a consciousness early in the third trimester. As such, as far as I am concerned, a fetus is a human starting in trimester number three. This is based on scientific studies, not some emotional feeling about what I think looks like a baby. If a woman wants an abortion in the first two trimesters she should be able to do whatever she wants with her own body. Once there is an actual cluster of cells that can reasonably classified as a human and not simply overgrown sperm that is when the right to an abortion should no longer be as casual as a whim, if someone so wants. From third trimester and on, a woman should only be able to have an abortion if the pregnancy is threatening her life OR if the fetus is not viable. There is no reason for a woman with family and friends to die so that a motherless infant with no connections to the world can come to be. To say that someone who has a place in this world and is loved has a lower priority than an unborn, unconnected, probably unloved except by the mother is ludicrous. Likewise, if a medical professional establishes that a fetus can not survive, it is stupid to subject a woman to the pain and prolonged heartache of a failed pregnancy.
TL;DR version:
Abortions for all in the first two trimesters.
Abortions only if the mother's life is threatened or the fetus is unviable in the third trimester.
