EPIDURAL ANALGESIA AND UTERINE FUNCTION

Objective: To determine whether continuous epidural analgesia with bupivacaine and fentanyl affects the rate of cervical dilation and myometrial contractility. Methods: In a 5-week period, 62 consecutive women who received standardized epidural analgesia were matched with the next two groups of 124 consecutive women of the same parity who did not receive epidural analgesia. The outcome variables were uterine activity, rate of cervical dilation, oxytocin therapy, and operative deliveries. Results: Continuous epidural analgesia with bupivacaine and fentanyl did not result in a change in myometrial contractility in the first hour after the initiation of analgesia. However, despite more oxytocin therapy, the rate of cervical dilation was significantly lower in the epidural group than in the nonepidural group (1.9 versus 5.6 cm/hour, P <.001). Operative deliveries were more common in patients with epidural analgesia than in those without it (12 of 62 versus two of 124, P <.001). Conclusion: After epidural analgesia, myometrial contractility is maintained with oxytocin, but the ability of the uterus to dilate the cervix is reduced significantly.