2,130. A Placenta Before and After a Fetus

Hilchos Issurei Biah 10:14

If a woman expels a placenta, she observes the same rules as follow to the birth of a boy and a girl. This is not because a placenta is a fetus (because it isn’t) but because there’s no placenta without a fetus. If she expels a fetus and later a placenta, we are concerned about the placenta and treat it like a fetus. We don’t assume that it’s the placenta of the fetus that she miscarried because we only attribute expelling a placenta to a viable birth. Therefore, if the woman delivered a viable baby and then discharged a placenta we attribute it to that birth, even after 23 days. We don’t assume that there was a second fetus, but rather that the live child ripped through the placenta while being born.

Hilchos Issurei Biah 10:15

If a woman expels a placenta and later delivers a viable baby, we must be concerned that the placenta came from another fetus; we don’t attribute it to the child that was born later because it’s uncommon for a placenta to come out before the fetus. If part of the placenta came out on Sunday and part on Monday, we act stringently by counting her impure days from Sunday and her pure days from Monday.