ABSTRACT
The majority of women with urinary and/or anorectal incontinence are parous. This observation led to the hypothesis that vaginal delivery may damage the innervation of the pelvic floor sphincter musculature. Pudendal nerve injury during vaginal delivery is by far the most common cause of progressive nerve damage, thus accounting for the preponderance of pelvic floor disorders among women in middle age and the elderly. An increased pudendal nerve terminal motor latency was found in 42% of women 48 h after vaginal delivery, but in none of the women delivered by cesarean section. The use of forceps during vaginal delivery increases the risk of damage to the pudendal nerves. Episiotomy and perineal tears not involving the external anal sphincter muscle did not add to pudendal nerve damage after vaginal delivery. Damage to the innervation of the external anal sphincter muscle may occur by direct factors, of which vaginal delivery and obstetric sphincter trauma are but two.
