As the baby and uterus grow during pregnancy, there is extra pressure and stress placed on the bladder – making it easier for any exertion, like laughing or sneezing, to push urine out of the bladder. Most women who have incontinence during pregnancy return to full continence after delivery as the birth canal heals.
During labor, the pressures generated by pushing and the delivery can damage the pelvic tissues and nerves that lie on each side of the birth canal. Over time and with age, the normal supporting tissues of the bladder, uterus and rectum weaken, adding to the effect of childbirth injuries. That said, the vast majority of women who give birth do not have any residual effects of incontinence within a few months after birth.