Thorp J A, McNitt J D, Leppert P C
Birth. 1990 Sep;17(3):157-62. doi: 10.1111/j.1523-536x.1990.tb00725.x.
The effects of epidural analgesia on first labors have been studied by Thorp and colleagues. One study has been published and is the subject of a question-and-answer discussion, presented here. In this study 711 consecutive nulliparous women at term, with spontaneous onset of labor and cephalic presentation, were divided into one group (n = 447) who received epidural analgesia in labor and another group (n = 264) who received narcotics or no analgesia. The frequency of cesarean section for dystocia was significantly greater (p less than 0.005) in the epidural group (10.3%) than in the nonepidural group (3.8%), even after selection bias was corrected and the variables of maternal age and race; gestational age; cervical dilatation on admission; use, duration, and maximum infusion rate of oxytocin; labor duration; presence of meconium; and birth weight were controlled. For both groups the frequency of cesarean section for fetal distress was similar (p less than 0.20), and the frequency of low Apgar scores at 5 minutes and cord blood gas values showed no significant differences. The authors concluded that "epidural analgesia in labor may increase the incidence of cesarean section for dystocia in nulliparous women".
索普及其同事研究了硬膜外镇痛对初产妇分娩的影响。一项相关研究已发表，本文将对其进行问答讨论。在这项研究中，711名足月、自然临产且头先露的初产妇被分为两组，一组（n = 447）在分娩时接受硬膜外镇痛，另一组（n = 264）接受麻醉剂或不接受镇痛。即使在纠正了选择偏倚并控制了产妇年龄、种族、孕周、入院时宫颈扩张程度、缩宫素的使用、持续时间和最大输注速率、产程、胎粪情况及出生体重等变量后，硬膜外组因难产而行剖宫产的频率（10.3%）仍显著高于非硬膜外组（3.8%）（p < 0.005）。两组因胎儿窘迫而行剖宫产的频率相似（p < 0.20），5分钟时低Apgar评分的频率及脐血气值均无显著差异。作者得出结论：“分娩时硬膜外镇痛可能会增加初产妇因难产而行剖宫产的发生率”。
