Factors associated with the use of episiotomy during vaginal delivery

Objective: To examine factors associated with the performance of episiotomy. Methods: A retrospective review was performed on 8647 deliveries during 1991 and 1992 at five medical centers. Episiotomy rates were compared based on variables involving patient demographics, obstetric condition, and physician factors for the 6458 vaginal deliveries in the sample. Logistic regression modeling using variables associated in bivariate analysis was performed to examine independent effects of each variable. Results: Several characteristics of the patient, her clinical status, and physician factors were all associated with episiotomy use. The strongest independent predictors of episiotomy were nulliparity (odds ratio [OR] 4.10, 95% confidence interval [CI] 3.59-4.68) and the use of forceps (OR 5.03, 95% CI 3.39-7.46) or Vacuum extraction (OR 3.78, 95% CI 2.36-6.04). Provider specialty and the site of care were also associated independently with episiotomy. Episiotomy use was also associated with major perineal lacerations and an increased length of hospital stay. Conclusion: Although differences in episiotomy rates mainly reflect clinical circumstances, important site-to-site variations and interspecialty differences point to potential areas where physician behaviors influence the performance of episiotomy.