Question
With regard to firstborns by C-section:
Why is a C-section interpreted to be NOT a form of "opening the womb", when that interpretation forbids the doing of the Torah mitzvah of Pidyon Haben?
Answer
"Peter Rechem" (Bamidbar 18 15) is understood by our sages to be the baby born that opens the womb, a cesarean baby doesn't open the womb, it is opened for him, therefor exempt from Pidyon - redeeming.
(Bechorot 19a; Tanchuma Bo 11)
