 Some Rabbinic authorities further consider the possibility (generally not accepted) that a union that by definition cannot lead to pregnancy would amount to "spilling seed", the sin of Onan ( ).A woman's obligation being overridden in Jewish law by the danger of childbirth which opens up the option of them taking steps toward preventing pregnancy.The option of contraception is raised by the Talmud (Tractate Yevamot 12b), where the use of a pessary is discussed for women who are too young to get pregnant, presently pregnant, or nursing.