Vaginal birth can damage the muscle that supports the bladder.
Damage during vaginal birth to a muscle that supports the bladder and uterus may eventually cause uterine prolapse, a weakening of the pelvic-floor muscles that allows the uterus to drop into the vagina. Risk factors include having one or more vaginal deliveries, giving birth to a large baby and being older at the time of delivery.
University of Michigan researchers found damage to the levator ani muscle in 55 percent of women with prolapse compared with only 16 percent without. The next step, say researchers, is to discover how to prevent injury to this muscle during vaginal birth. In the meantime, some women choose to have a Cesarean section to prevent pelvic-floor damage, although research on this option is mixed. Avoiding use of forceps during delivery may help protect the pelvic-floor muscles.