For your consideration (from Talmud)
“if a woman travails to give birth [and it is feared she may die], one may sever the fetus from her womb and extract it, member by member, for her life takes precedence over his” (Oho. 7:6). This is the case only as long as the fetus has not emerged into the world, when it is not a life at all and “it may be killed and the mother saved” (Rashi and Meiri, Sanh. 72b). But, from the moment that the greater part of the fetus has emerged into the world – either its head only, or its greater part – it may not be touched, even if it endangers the mother’s life: “ein doḥin nefesh mi-penei nefesh” (“one may not reject one life to save another” – Oho. and Sanh. ibid.).
