"The central rabbinic text concerning abortion,
M. Ohalot 7:6, states that if a woman is having difficulty giving birth, the midwife dismembers the fetus
in utero to extract it to save the mother’s life, even in a full-term pregnancy. In such a difficult birthing situation,
the fetus is considered a pursuer (rodef), pursuing the mother to kill her, and therefore can be killed to protect her. In Talmudic discussions concerning a pursuer, it is deemed appropriate to kill the pursuer (without incurring liability) to save the life of the one pursued (B.
Sanhedrin 72b). Another position holds that the fetus, prior to the birth of its head,
has not attained the status of human (nefesh). Whichever position is accepted, the fetus is to be dismembered in the case of a difficult birth."
"Another description of the fetus is that
it is “a limb of its mother” (B.
Ḥullin 58a, B.
Bava Kama 78b-79a, B.
Sanhedrin 80a, B.
Nazir 51a, B.
Gittin 23b, and B. Terumot 25a), indicating that
it has no independent existence."
"Women were
not considered to be obligated in the commandment of procreation(
M. Yevamot 6:6). The discussion in B.
Yevamot 65b deals with the case of Yehudit, the wife of Rabbi Ḥiyya, who suffered greatly with very difficult pregnancies—two sets of twins, one in which one baby’s birth preceded his twin by almost three months. Yehudit disguised herself and went before Rabbi Ḥiyya to ask whether women were obligated in procreation. When he responded in the negative, she partook of
sama d’akarta/d’akara. This has been normally understood as being a contraceptive drug, but
the root ’kr means both infertile and uprooting. It could, therefore, refer to an abortifacient uprooting a pregnancy."
"Tosafot (B.
Sanhedrin 59a,
d.h., leka midam; B.
Ḥullin 33a,
d.h., eḥad oved kokhavim) extended the Gentile prohibition of abortion to Jews but without legal liability; in other words,
they considered it forbidden, but with no legal consequences. Elsewhere (Tosafot, B.
Niddah 44b,
d.h., ihu maet bereisha), they stated that it is permitted to kill the fetus."
"At no point in the responsa literature up to the twentieth century, then, is abortion considered murder. Many responsa allow abortion
even when the mother’s life is not at stake, and
lenient positions outnumber more stringent positions. Many more such responsa may have been given privately and not published. The bottom line is that
the mother’s life always takes precedence over the life of the fetus until the head or majority of the body is born. Even then
there is a preference to save the life of the mother if both will die. Disputes arise when the health and well-being of the mother are at stake."