http://www.aish.com/ci/sam/48954946.html
...As a general rule, abortion in Judaism is permitted only if there is a direct threat to the life of the mother by carrying the fetus to term or through the act of childbirth.
In such a circumstance, the baby is considered tantamount to a rodef, a pursuer after the mother with the intent to kill her. Nevertheless, as explained in the Mishna, if it would be possible to save the mother by maiming the fetus, such as by amputating a limb, abortion would be forbidden.
Despite the classification of the fetus as a pursuer, once the baby’s head or most of its body has been delivered, the baby’s life is considered equal to the mother’s, and we may not choose one life over another, because it is considered as though they are both pursuing each other.
Abortion is wrong, no matter what the excuse, health of the mother is a straw man argument.