I feel that as a society we really can't stop abortions. Whether or not getting abortions is legal, girls and women who really feel it's best that their embryo is aborted will find a way to get it done. Others will feel forced to give birth no matter what, and feel that they live in an oppressed society which lacks compassion for their plight.
Some girls/women feel desperate to conceive and carry a child, others feel desperate not to. Some see human life as sacred - more sacred that other forms of life, such as Trish pointed out, trees, rocks and all of Nature; still others see all life as equally sacred yet temporary. Each and all hold a feeling or an opinion on the issue. Yet, those in all categories who believe in the soul, believe it can never die. (Trish sparked an awesome thing to consider - doesn't life really start with the soul or spirit?)
The core conundrum is in forcing an opinion on everyone else that would drastically alter their lives and bodies. We have the privilege to live in a society where certain freedoms of choice remain intact, even if it means it goes against something that we may personally believe in, or could never willingly take part in. Still other things that cause unwanted or devastating pregnancies are out of our control entirely; like promiscuous sex, incest, failed birth control, and rape. Or just plain ol' "ooops." Isn't this truly where abortion begins?
I guess it all boils down to the human condition. In a perfect world there would be no abortion. In a perfect world, there would be none of the above infractions that lead to abortion. Even still, a perfect world would not be facing dictatorships, over-population, severe deformities, poverty, starvation, disease, foster care horror stories, and the selling of unwanted children. We may not feel that it's seemly, but life is a dirty deal sometimes. Because we as a society can't mandate pristine behaviors and divine intellect, there will always be unwanted pregnancies, unwanted and abused children and misuse of sexuality. Should we somehow gain the ability to shuffle our deck without the need for drama and hard lessons, we would see Heaven on Earth. Until then, the cycle of a race with many, many lessons to learn will continue...