Episiotomy: risks of dehiscence and rectovaginal fistula.

The obstetric literature was reviewed to assess the risk of episiotomy dehiscence and rectovaginal fistula formation from routine episiotomy, with and without third- and fourth-degree laceration into the rectal sphincter or rectal mucosa, respectively. Strong evidence suggests that elective episiotomy predisposes to severe 3rd and 4th degree perineal lacerations and that episiotomy dehiscence with rectovaginal fistula formation is strongly related to 3rd and 4th degree perineal lacerations.