Snapshot A 35-year-old G1P0 woman is in the labor and delivery unit and has been in labor for the past 6 hours. Her pregnancy was significant for gestational diabetes. The woman elected to have epidural anesthesia during labor, and forceps are used to aid delivery of her baby. The obstetrician examines the woman's vagina and perineum after the delivery, and notes she has a third-degree perineal laceration. Introduction Overview perineal lacerations are lacerations associated with vaginal childbirth that may occur when the vagina and surrounding tissues stretch during delivery 1st-degree laceration injury to the skin and subcutaneous tissue of the perineum and vaginal epithelium only 2nd-degree laceration injury extends into the fascia and perineal muscles 3rd-degree laceration injury extends through the fascia and perineal muscles and involves some or all of the fibers of the anal sphincter muscles 4th-degree laceration injury to the perineum that involves both the anal sphincters (external and internal) and the anal mucosa Epidemiology > 85% of women who undergo a vaginal delivey will suffer some degree of perineal tear 3-10% of all vaginal deliveries result in a 3rd-degree or 4th-degree tear Risk factors forceps delivery nulliparity large for gestational age or birthweight longer duration of 2nd stage of labor ETIOLOGY Pathophysiology mechanism of injury vaginal delivery causes extensive stretching of the vagina and surrounding tissue Presentation Symptoms perineal pain may be exacerbated by sitting, walking, urinating, and bowel movements Physical exam laceration of the perineum and surrounding tissue, closed by sutures Treatment Surgical closure of laceration with sutures 1st- and 2nd-degree tears anal sphincter and mucosa repair 3rd- and 4th-degree tears Complications Perineal wound dehiscence incidence up to 25% of 3rd- and 4th-degree lacerations Perineal wound infection incidence up to 20% of 3rd- and 4th-degree lacerations