Needless to say, the Jewish view on abortion is not a subject that can be fully explained in a few e-mail sentences. However, I will try to give you some of the highlights.
Judaism is, of course, pro-life. Every life is precious and no one has the unilateral freedom to decide that an unborn fetus has no right to be born. If one is threatened with death and the only way he could survive is by killing someone else, he may not do so. Generally, we may not assume that our life is more valuable than another's. That having been said, there are other rules which may have an effect on the unborn. For example, Jewish law recognizes that where a murderer is chasing his intended victim and attempting to kill him, anyone can step in to save the victim, even if the murderer ends up dead as a result. This concept has been applied in the situation of a pregnant woman whose labor and delivery create complications for her. If it becomes necessary to abort the fetus in order to save the mother, Jewish law views the fetus as the "murderer" and the mother as the "victim". In such a case, abortion would probably be performed.
Conceptually, Jewish law does not give us absolute discretion over our own bodies. One does not have the right to mutilate oneself while alive, nor may one, under normal circumstance donate body organs after death. Our bodies do not belong to us - they belong to God. As such, a woman would be limited in what she could do to her pregnat body as well.
This is by no means the entire story, but I hope it helps.
