Recognizing the preciousness of potential life in every fetus, Jewish law generally does not permit the destruction of a fetus without cause. Where there is cause, Judaism permits abortion (Statement on the Permissibility of Abortion, Committee on Jewish Law and Standards, 1983). 

In general, Jewish law prohibits needlessly “wounding the body” (habbalah) (Babylonian Talmud Bava Kama 90b). Wounding (e.g., surgery) is only permitted in order to heal.

Therefore, since the fetus is considered part of its mother’s body, Jewish law permits abortion to protect the mother’s health. Jewish law requires an abortion to protect the mother’s life because the mother’s life always takes precedence over the potential life of the fetus within her.

That is why even the strictest interpretations of Jewish law require an abortion to protect the mother’s life at all stages of the pregnancy, even after labor has begun (Mishnah Oholot 7:6). 

The Mishnah permits an abortion until the head or most of the fetal body has emerged from the mother during birth. Even at this latest stage of the birth process, Jewish authorities still allow the fetus to be aborted if necessary to protect the mother’s life. (See Responsa Melammed L’Ho’il  Vol. II, Yoreh Deah, no. 69). 

In such cases, the physician can act on behalf of the mother, in effect as her agent.

Maimonides treats the fetus “like” a pursuer, a rodef, when the fetus endangers the mother’s health or life. Just as a pursuer must be stopped from endangering another by whatever means necessary, the fetus must be stopped from endangering its mother, even though its threat is not intentional. (Mishneh Torah Hilkhot Rotzeah u’Shmirat HaNefesh 1.9).  

Jewish law permits abortion at all stages of pregnancy to protect the mother’s health.

In general, Jewish approaches to medicine prefer the most effective and least physically invasive methods possible to protect life and health. Therefore, Jewish law permits both medications and surgical abortions (Maimonides, ibid).

While Jewish law favors abortions performed as early as possible, late-term abortions are allowed and sometimes required, particularly when late-term complications can endanger a woman’s life or health, which includes her physical and mental health and her ability to bear future children. 

Jewish law has long recognized a woman’s overall health includes her mental health.

Thus, an abortion may be performed to protect a woman from emotional distress. The classic example, though not relevant today, is found in the Talmud: An abortion must be performed on a pregnant woman condemned to death to save her from the emotional distress of miscarrying as the death sentence is carried out (Babylonian Talmud Arakhin 7a).

This precedent led later rabbis to consider under what other conditions an abortion could be permitted for maternal distress (Responsa She’elat Ya’avetz 1.43, Responsa Tzitz Eliezer 9.51).

The Conservative Movement’s Committee on Jewish Law and Standards (CJLS) has passed teshuvot permitting the abortion of a severely deformed fetus or a fetus with little chance for survival (such as with Tay Sachs), even in the eighth or ninth month, if continuing the pregnancy would cause significant emotional distress to the mother (e.g., Rabbi Avram Reisner, “Peri and Neonatology: The Matter of Limiting Treatment,” YD 339.1995, CJLS Responsa 1991-2000).

This consideration would clearly apply to permit abortion in cases of rape or incest (see Tzitz Eliezer reference above). 

Some rabbinic authorities also permit abortion to protect the health of a woman’s current children, for example, to protect her milk supply if she is nursing (Responsa Beit Yehudah, Even HaEzer, 14) or, by extension, her ability to support them.