The effect of epidural analgesia on rates of episiotomy use and episiotomy extension in an inner-city hospital

OBJECTIVE: To determine the relationship between epidural analgesia and episiotomy usage and episiotomy extension in parturients delivering vaginally. METHODS: A database of 20 888 women experiencing spontaneous vaginal delivery at Grady Memorial Hospital from 1990 to 1995 was examined to identify those receiving epidural analgesia. Patients who underwent epidural catheter placement and had adequate perineal anesthesia at delivery comprised the epidural group, and all others comprised the control group. Demographic characteristics and obstetric outcomes were compared. Univariate and multivariate analyses were used to test the association between epidural analgesia, rates of episiotomy and episiotomy extension. RESULTS: Of the 20888 women experiencing spontaneous vaginal deliveries 6785 (32.5%) received epidural analgesia. Women receiving epidural analgesia were more likely than those not receiving epidural analgesia to be African-American and nulliparous, and to have an occiput posterior presentation. Women receiving epidural analgesia were also more likely to receive an episiotomy (27.8% vs. 13.1%, odds ratio (OR) 2.56, 95% confidence interval (CI) 2.38-2.75) and were less likely to experience a second-degree perineal laceration (11.6% vs. 14.4%, OR 0.75, 95% CI 0.69-0.82) or a third- or fourth-degree extension (8.9% vs. 12.4%, OR 0.81, 95% CI 0.68-0.97). When the results were adjusted for nulliparity, posterior presentation, macrosomia, shoulder dystocia and prolonged second stage, epidural analgesia remained independently associated with receipt of episiotomy (OR 1.97, 95% CI 1.88-2.06) and reduced episiotomy extension (OR 0.74, 95% CI 0.54-0.94). CONCLUSION: Epidural analgesia increases the rates of episiotomy use, and decreases the rate of episiotomy extension, independently of clinical factors associated with episiotomy.