Our Posuk says “And when the days of her purification are fulfilled, for a son, or for a daughter, she shall bring a lamb of the first year for an Olah, and a young dove, or a turtle-dove, for a Chatos”. The obvious question is… Why does a woman who gave birth have to bring a Korbon Chatos – a sin offering? What sin has she committed to require her to bring such a Korbon?
Some Meforshim explain, since during her labor pains, she might have made an oath to never have another baby, she therefore brings a Korbon to atone for that oath and nullify it. Kli Yakar offers a different explanation. He says, the atonement is not for this woman but rather for Chavah – the first
woman. Since pain from pregnancy and labor is a punishment for Chavah’s sin, eating from the Aitz HaDaas (tree of Knowledge), this woman brings a Korban now to atone Chava’s sin. After going through all the pain of her pregnancy and labor she wants to bring an end to this suffering and brings a Korbon for Chava’s Aveira.