The effect of intrapartum epidural analgesia on nulliparous labor: a randomized, controlled, prospective trial. Upright versus recumbent position in the second stage of labour in women with combined spinal-epidural analgesia. Randomized trial of epidural versus intravenous analgesia during labor. The influence of epidural analgesia on cesarean delivery rates: a randomized, prospective clinical trial.
Our purpose was to determine the effect of epidural analgesia on nulliparous labor and delivery.
                Normal term nulliparous women in early spontaneous labor were randomized to receive either narcotic or epidural analgesia.
                When compared with the group receiving narcotic analgesia (n = 45), the group receiving epidural analgesia (n = 48) had a significant prolongation in the first and second stages of labor, an increased requirement for oxytocin augmentation, and a significant slowing in the rate of cervical dilatation. Epidural analgesia was associated with a significant increase in malposition (4.4% vs 18.8%, p < 0.05). Cesarean delivery occurred more frequently in the epidural group (2.2% vs 25%, p < 0.05), primarily related to an increase in cesarean section for dystocia (2.2% vs 16.7%, p < 0.05).
                In a randomized, controlled, prospective trial epidural analgesia resulted in a significant prolongation in the first and second stages of labor and a significant increase in the frequency of cesarean delivery, primarily related to dystocia. Neuraxial blockade is widely used for pain relief in labour. This form of analgesia may be associated with an increase in instrumental delivery rates due to dystocia. 'Traditional' epidurals cause motor blockade and hence immobility. Using a low dose anaesthetic-opioid combination with either epidural or combined spinal-epidural, selective sensory blockade can be achieved, allowing mobility as well as pain relief. In this study, we randomised women with combined spinal-epidural analgesia either to mobilise (upright group n = 25) or to remain recumbent (n = 41) in the second stage of labour. We found women in the upright group had significantly shorter total second stage, (132 vs 109 min,P = 0.019) particularly during the pushing phase (73 vs 51 min, P = 0.011). Although there were fewer instrumental deliveries in the upright group, this was not statistically significant. Women who were randomised to the upright group, did actually mobilise. We conclude that mobilisation in the second stage of labour is possible, and may reduce the length of the second stage. To compare the effects of epidural analgesia with intravenous (IV) analgesia on the outcome of labor.
                Thirteen hundred thirty women with uncomplicated term pregnancies and in spontaneous labor were randomized to be offered epidural bupivacaine-fentanyl or IV meperidine analgesia during labor.
                Comparison of the allocation groups by intent to treat revealed a significant association between epidural allocation and operative delivery for dystocia. However, only 65% of each randomization group accepted the allocated treatment. Four hundred thirty-seven women accepted and received meperidine as allocated, and they were compared with 432 women accepting epidural allocation. Significant associations resulted between epidural administration and prolongation of labor, increased rate of oxytocin administration, chorioamnionitis, low forceps, and cesarean delivery. Because of the high rate of noncompliance with treatment allocation, a multifactorial regression analysis was performed on the entire cohort, and a twofold relative risk of cesarean delivery persisted in association with epidural treatment. The impact of epidural treatment on cesarean delivery was significant for both nulliparous and parous women (risk ratios 2.55 and 3.81, respectively). Epidural analgesia provided significantly better pain relief in labor than did parenteral meperidine.
                Although labor epidural analgesia is superior to meperidine for pain relief, labor is prolonged, uterine infection is increased, and the number of operative deliveries are increased. A two- to fourfold increased risk of cesarean delivery is associated with epidural treatment in both nulliparous and parous women. The effects of epidural analgesia on the progress of labor are controversial. The objective of this study was to determine the effect of epidural analgesia on cesarean delivery rates in a population of patients randomly assigned to receive either epidural analgesia or intravenous opioids for intrapartum pain relief.
                From January 1995 to May 1996, 318 spontaneously laboring, term, nulliparous patients were randomly assigned to receive either intravenous opioids or epidural analgesia for pain relief. Labor was managed according to the principles of active management of labor. Cesarean delivery was performed for obstetric indications. Data analysis was conducted on an intent-to-treat basis. A subanalysis was subsequently performed on patients who were compliant with the allocated form of treatment.
                One hundred sixty-two patients were randomly assigned to receive intravenous meperidine and 156 were randomly assigned to receive epidural analgesia. Maternal age, gravidity, race, gestational age, and cervical dilatation at admission and at first analgesic dose did not differ between the groups. Intent-to-treat data analysis revealed no significant difference in the cesarean delivery rate between the 2 groups, being 13.6% in the opioid group and 9.6% in the epidural group (relative risk 0.70, 95% confidence interval 0.38-1.31, P >.05). Cesarean delivery rates for the indication of dystocia also did not differ, being 10.5% in the opioid group and 5.8% in the epidural group (relative risk 0.56, 95% confidence interval 0.26-1.21, P >.05). Subanalysis of the data from patients who were compliant with the allocated form of treatment revealed that patients in the epidural group (n = 147) were 3 times more likely to have an active phase duration >/=8 hours and were 10 times more likely to require >/=2 hours in the second stage of labor than were those in the opioid group (n = 78). There were no significant differences in cesarean delivery rates in this subanalysis, being 7.7% in the opioid group and 8.8% in the epidural group (relative risk 1.15, 95% confidence interval 0.45-2.91, P >. 05). The cesarean delivery rates for dystocia were also similar in the subanalysis, being 3.8% in the opioid group and 5.5% in the epidural group (relative risk 1.42, 95% confidence interval 0.39-5. 22, P >.05).
                Epidural analgesia provides safe and effective intrapartum pain control and may be administered without undesirable effects on labor outcome.
There is insufficient evidence to support the hypothesis that discontinuing epidural analgesia late in labour reduces the rate of instrumental delivery. There is evidence that it increases the rate of inadequate pain relief in the second stage of labour. The practice of discontinuing epidurals is widespread and the size of the reduction in instrumental delivery rate could be clinically important; therefore, we recommend a larger study than those included in this review be undertaken to determine whether this effect is real or has occurred by chance, and to provide stronger evidence about the safety aspects.