The Hebrew word tum’ah is typically translated as ritual impurity. Tum’ah is most relevant in modern times to describe a woman’s status during and after her menstrual cycle ;‘impurity’ is a crass, misnomer of a translation. A better translation/explanation for the word is ‘a state-of-restrictedness.’ To what is she restricted? During ancient times, a person, male or female, with tum’ah was prevented from bringing a sacrifice to the Temple; and even today a woman in this restricted state must desist from conjugal relations until the status is removed. This week’s parsha contains the following: And when the days of her (a birthing mother’s) tum’ah are fulfilled, for a son, or for a daughter, she shall bring a lamb of the first year for a burnt-offering, and a young pigeon, or a turtle-dove, for a sin-offering, unto the door of the tent of meeting, unto the priest.(Leviticus 12:6) The burnt-offering was part of her ritual to remove the tum’ah – does the sin-offering connote some type of negativity concomitant to bearing children?
Explains the Talmud:
R.Simeon b. Yohai was asked by his disciples: Why did the Torah ordain that a woman after childbirth should bring a sin-offering? He replied: When she kneels to bear the child she swears recklessly that she will have no relations with her husband. The Torah, therefore, ordained that she should bring a sacrifice [in order to absolve her of her oath]. (B.T. Niddah 31b).