Kerisos 1:4-5

Krisos 1:4

The following women bring an offering that is not eaten: if a woman miscarried and the nature of the miscarriage is unknown, or if two women miscarry, one of a kind that doesn’t require a sacrifice and one of a kind that does (and it is not known whose is whose). Rabbi Yosi said that this is the case when the women went in different directions but if they stayed in the same case, they jointly bring one offering, which is eaten.

Krisos 1:5

The following women do not bring an offering at all: a woman who miscarries a fetus filled with water, blood or shreds; if the miscarriage resembles a fish, locusts, insects or creeping things; if a woman miscarries on the fortieth day of pregnancy (or sooner), or if the miscarriage is removed via a c-section. Rabbi Shimon requires a woman to bring a sacrifice in the case of one removed via c-section.