Cesarean delivery: A randomized trial of epidural analgesia versus intravenous meperidine analgesia during labor in nulliparous women

Background: Controversy concerning increased cesarean births as a result of epidural analgesia for relief of labor pain has been attributed, in large part, to difficulties interpreting published studies because of design flaws. In this study, the authors compared epidural analgesia to intravenous meperidine analgesia using patient-controlled devices during labor to evaluate the effects of labor epidural analgesia, primarily on the rate of cesarean deliveries while minimizing limitations attributable to study design. Methods: Four hundred fifty-nine nulliparous women in spontaneous labor at term were randomly assigned to receive either epidural analgesia or intravenous meperidine analgesia. Epidural analgesia was initiated with 0.25% bupivacaine and was maintained with 0.0625% bupivacaine and fentanyl 2 μg/ml at 6 ml/h with 5-ml bolus doses every 15 min as needed using a patient-controlled pump. Women in the intravenous analgesia group received 50 mg meperidine with 25 mg promethazine hydrochloride as an initial bolus, followed by 15 mg meperidine every 10 min as needed, using a patient-controlled pump. A written procedural manual that prescribed the intrapartum obstetric management was followed for each woman randomized in the study. Results: A total of 226 women were randomized to receive epidural analgesia, and 233 women were randomized to receive intravenous meperidine analgesia. Protocol violations occurred in 8% (38 of 459) of women. There was no difference in the rate of cesarean deliveries between the two analgesia groups (epidural analgesia, 7% [16 of 226; 95% confidence interval, 4-11%] vs. intravenous meperidine analgesia, 9% [20 of 233; 95% confidence interval, 5-13%]; P = 0.61). Significantly more women randomized to epidural analgesia had forceps deliveries compared with those randomized to meperidine analgesia (12% [26 of 226] vs. 3% [7 of 233]; P < 0.001). Women who received epidural analgesia reported lower pain scores during labor and delivery compared with women who received intravenous meperidine analgesia. Conclusions: Epidural analgesia compared with intravenous meperidine analgesia during labor does not increase cesarean deliveries in nulliparous women.