Episiotomy is commonly performed during delivery in the belief that it prevents perineal lacerations, pelvic floor relaxations, and incontinence, and that it protects the infant from intrapartum trauma and asphyxia. Several studies have cast doubt on the benefits of episiotomy, in particular the ability to prevent perineal lacerations. Sartore and colleagues conducted a study to examine the effect of episiotomy on lower pelvic muscle strength and dysfunction to determine if it helps prevent urinary incontinence, fecal incontinence, and vaginal prolapse.

The study included 519 consecutive primiparous women who delivered singleton vertex infants vaginally in an Italian teaching hospital. All of the deliveries were carried out in the lithotomy position following the same protocol. Exclusion criteria included: cesarean delivery; severe perineal lacerations; preterm, breech, and operative deliveries; and women who had a history of urinary incontinence, fecal incontinence, or vaginal or anal surgery. The study compared 254 women who received mediolateral episiotomy with 265 women who delivered with intact perineum or spontaneous first- or second-degree lacerations. Participants were assessed during the puerperium for pelvic floor function by history and a series of investigations. Histories focused on symptoms of stress and urge incontinence, anal incontinence, urinary frequency, dyspareunia, and pelvic pain. Physical examination included testing for stress and urge incontinence and strength of pelvic floor musculature using standardized scoring systems. Each patient had vaginal manometry and urine stream interruption testing.

Women who received episiotomy were more likely to receive epidural analgesia and had infants of higher birth weight. The two groups were comparable in all other respects. In the episiotomy group, 65.8 percent had no relevant symptoms compared with 75.8 percent of women in the no-episiotomy group. Women who did not receive episiotomy were significantly more likely to be completely symptom-free. Dyspareunia and pelvic pain were significantly more common in women who had episiotomy. Anal incontinence also was more common in this group but affected only a few women. No significant difference was found between the groups in urinary symptoms or signs. The groups did not differ significantly in the incidence of prolapse, but results of vaginal manometry and digital testing were significantly worse in women in the episiotomy groups.

The authors conclude that mediolateral episiotomy is associated with decreased pelvic floor muscle strength and more dyspareunia and pelvic pain than spontaneous minor perineal lacerations. They also conclude that the procedure does not protect against urinary and anal incontinence and vaginal prolapse. Although the higher rates of epidural analgesia could have influenced the results, the authors question the role of episiotomy in vaginal delivery.