My aunt is a doctor..She talked to us about this in her intern year..Now-a-days to save the vagina from damage, during the delivery doctors cut it a little with scissors so that their is no barbaric damage..& then saw it up..& it some cases it becomes tighter than before..! & my aunt said, in that one moment, there is so much happening, & the actual birthing process, as in the labor pains are so massive, that, that one moment of pain is actually bearable...& in case of cesarean, you are given an injection on your spine, & as a result, most women have lower back pains for the rest of their lives.