The effects of epidural anesthesia on type of delivery

A retrospective cohort study of 626 low-risk patients admitted for labor and delivery under the care of a family physician was designed to test the hypothesis that epidural anesthesia increases the frequency of instrumental and operative deliveries. The crude odds ratio of instrumental or operative delivery in women electing to have epidural anesthesia was 9.56 (95 percent confidence interval, 5.57 to 16.40; P less than 0.001). Controlling for bias by multivariate analysis did not change the conclusion indicated by the crude odds ratio--use of elective epidural anesthesia results in markedly increased odds of instrumental or operative delivery.