This article from aish.com discusses the relevant issues from the Jewish perspective:
http://www.aish.com/ci/sam/48954946.htmlAbortion in Jewish Law
by Daniel Eisenberg, M.D.
The traditional Jewish view does not fit conveniently into the major "camps" in the current debate.
As abortion resurfaces as a political issue in the upcoming U.S. presidential election, it is worthwhile to investigate the Jewish approach to the issue. The traditional Jewish view of abortion does not fit conveniently into any of the major "camps" in the current American abortion debate.
We neither ban abortion completely, nor do we allow indiscriminate abortion "on demand."A woman may feel that until the fetus is born, it is a part of her body, and therefore she retains the right to abort an unwanted pregnancy. Does Judaism recognize a right to "choose" abortion? In what situations does Jewish law sanction abortion?
To gain a clear understanding of when abortion is permitted (or even required) and when it is forbidden requires an appreciation of certain nuances of halacha (Jewish law) which govern the status of the fetus.1
The easiest way to conceptualize a fetus in halacha is to imagine it as a full-fledged human being -- but not quite.2
In most circumstances, the fetus is treated like any other "person." Generally, one may not deliberately harm a fetus. But while it would seem obvious that Judaism holds accountable one who purposefully causes a woman to miscarry, sanctions are even placed upon one who strikes a pregnant woman causing an unintentional miscarriage.3 That is not to say that all rabbinical authorities consider abortion to be murder.
The fact that the Torah requires a monetary payment for causing a miscarriage is interpreted by some Rabbis to indicate that abortion is not a capital crime4 and by others as merely indicating that one is not executed for performing an abortion, even though it is a type of murder.5 There is even disagreement regarding whether the prohibition of abortion is Biblical or Rabbinic. Nevertheless, it is universally agreed that the fetus will become a full-fledged human being and there must be a very compelling reason to allow for abortion.
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 pursuer6 after the mother with the intent to kill her.
Nevertheless, as explained in the Mishna,7 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.It is important to point out that the reason that the life of the fetus is subordinate to the mother is because the fetus is the cause of the mother's life-threatening condition, whether directly (e.g. due to toxemia, placenta previa, or breach position) or indirectly (e.g. exacerbation of underlying diabetes, kidney disease, or hypertension).8 A fetus may not be aborted to save the life of any other person whose life is not directly threatened by the fetus, such as use of fetal organs for transplant.Judaism recognizes psychiatric as well as physical factors in evaluating the potential threat that the fetus poses to the mother. However, the danger posed by the fetus (whether physical or emotional) must be both probable and substantial to justify abortion.9 The degree of mental illness that must be present to justify termination of a pregnancy has been widely debated by rabbinic scholars,10 without a clear consensus of opinion regarding the exact criteria for permitting abortion in such instances.11 Nevertheless, all agree that were a pregnancy to causes a woman to become truly suicidal, there would be grounds for abortion.12 However, several modern rabbinical experts ruled that since pregnancy-induced and post-partum depressions are treatable, abortion is not warranted.13
As a rule, Jewish law does not assign relative values to different lives.
Therefore, almost most major poskim (Rabbis qualified to decide matters of Jewish law) forbid abortion in cases of abnormalities or deformities found in a fetus. Rabbi Moshe Feinstein, one the greatest poskim of the past century, rules that even amniocentesis is forbidden if it is performed only to evaluate for birth defects for which the parents might request an abortion. Nevertheless, a test may be performed if a permitted action may result, such as performance of amniocentesis or drawing alpha-fetoprotein levels for improved peripartum or postpartum medical management.
While most poskim forbid abortion for "defective" fetuses, Rabbi Eliezar Yehuda Waldenberg is a notable exception. Rabbi Waldenberg allows first trimester abortion of a fetus that would be born with a deformity that would cause it to suffer, and termination of a fetus with a lethal fetal defect such as Tay Sachs up to the seventh month of gestation.14 The rabbinic experts also discuss the permissibility of abortion for mothers with German measles and babies with prenatal confirmed Down syndrome.
There is a difference of opinion regarding abortion for adultery or in other cases of impregnation from a relationship with someone Biblically forbidden. In cases of rape and incest, a key issue would be the emotional toll exacted from the mother in carrying the fetus to term. In cases of rape, Rabbi Shlomo Zalman Aurbach allows the woman to use methods which prevent pregnancy after intercourse.15 The same analysis used in other cases of emotional harm might be applied here. Cases of adultery interject additional considerations into the debate, with rulings ranging from prohibition to it being a mitzvah to abort.16
I have attempted to distill the essence of the traditional Jewish approach to abortion. Nevertheless, every woman's case is unique and special, and the parameters determining the permissibility of abortion within halacha are subtle and complex. It is crucial to remember that when faced with an actual patient, a competent halachic authority must be consulted in every case.