Timing of Initiating Epidural Analgesia and Mode of Delivery in Nulliparas: A Retrospective Experience Using Ropivacaine

Background: The timing of initiation of epidural analgesia and its causal relationship withmode of delivery is controversial. This retrospective investigation reviewsand determines whether early initiation of epidural analgesia in nulliparouswomen influences the rate of cesarean sections as well as other obstetric outcomemeasures.Methods: The nursing records of 1623 parturients who received epidural analgesiawere retrospectively reviewed. Of these, 704 nulliparous parturients whopresented in spontaneous labor or had spontaneous rupture of the membranesand received epidural analgesia with a regimen of ropivacaine and fentanylwere included in this study. All parturients received the epidural protocol followingtheir first request. Parturients were divided into early (n = 457) andlate (n = 247) groups according to cervical dilatation < 3 cm and ≧ 3 cm,respectively, when epidural analgesia was initiated. The mean primarycesarean section rate during the research period was calculated from themonthly report of the department of obstetrics and gynecology.Results: The mean primary cesarean section rate in the institution was 23.6% duringthe research period. The overall cesarean section rate was 13.4% (n = 704) inthe studied groups. The early group required more top-up epidural anestheticboluses, and had a higher cesarean section rate than the late group (16.4% vs.7.7%, p = 0.002). However, the cesarean section rates of both groups werelower than the mean primary cesarean section rate. No difference wasobserved between groups in the percentage of arrested labor as the primaryindication for cesarean section. Early epidural analgesia shortened the durationof the active phase of the first stage of vaginal delivery. No differencewas observed between groups in the duration of the second stage or theinstrumental vaginal delivery rate.Conclusions: The administration of epidural analgesia with a regimen of ropivacaine andfentanyl should not be delayed until cervical dilatation reaches 3 cm in nulliparaswho are in spontaneous labor or have spontaneous rupture of the membranes.The timing of epidural analgesia should be determined on an individualizedbasis.