2,125. C-Sections and Birth Impurity
Hilchos Issurei Biah 10:4
If a woman expels something white and, when cut open, a bone is found inside of it, she is ritually unclean for a birth. If she expels a sac filled with water, blood, threads like worms, or flesh, the woman need not be concerned about birth impurity because it’s so undeveloped.
Hilchos Issurei Biah 10:5
If a child is born via C-section, the mother is not ritually unclean from birth impurity. She keeps neither impure days nor pure days as per Leviticus 12:2, “When a woman conceives and gives birth to a male...,” i.e., these laws only apply when a woman gives birth from the place where she conceives. If a woman has a difficult delivery so she undergoes a C-section, the blood from her labor that comes from her womb is considered like zivah blood or niddah blood; the blood from the C-section is also ritually unclean. If no blood came from her womb, then she remains ritually clean. Even though the blood from her surgery is unclean, the woman is not rendered unclean until the blood comes from her genitals.