If a child was delivered by caesarean, the normal counts of the day of ritual impurity after birth, followed by a period of purity, do not apply, neither is the mother obligated to bring a sacrifice - that is the opinion of the Sages. However, Rabbi Shimon says that this child is like a child born in the normal manner, and its mother is subject to all the usual childbirth laws. What are their proofs?
The proof of the Sages is from the phrase, "When a woman conceives and gives birth to a boy..." This implies that the rules that follow will apply only to a case when she gives birth from the place where she conceived. Rabbi Shimon, however, bases his proof on the phrase that follows, "If she gives birth to a girl." The words "gives birth" are extra, and they include caesarean.
Art: Jan Steen - Twin Birth Celebration