Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Sidney Kimmel College of Medicine at Thomas Jefferson University, Philadelphia, PA.
Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Sidney Kimmel College of Medicine at Thomas Jefferson University, Philadelphia, PA.
Am J Obstet Gynecol. 2016 Mar;214(3):361.e1-6. doi: 10.1016/j.ajog.2015.12.042.
Guidelines for management of the second stage have been proposed since the 1800s and were created largely by expert opinion. Current retrospective data are mixed regarding differences in maternal and neonatal outcomes with a prolonged second stage. There are no randomized controlled trials that have evaluated whether extending the second stage of labor beyond current American College of Obstetricians and Gynecologists recommendations is beneficial.
The purpose of this study was to evaluate whether extending the length of labor in nulliparous women with prolonged second stage affects the incidence of cesarean delivery and maternal and neonatal outcomes.
We conducted a randomized controlled trial of nulliparous women with singleton gestations at 36 0/7 to 41 6/7 weeks gestation who reached the American College of Obstetricians and Gynecologists definition of prolonged second stage of labor, which is 3 hours with epidural anesthesia or 2 hours without epidural anesthesia. Women were assigned randomly to extended labor for at least 1 additional hour, or to usual labor, which was defined as expedited delivery via cesarean or operative vaginal delivery. The exclusion criteria were intrauterine fetal death, planned cesarean delivery, age <18 years, and suspected major fetal anomaly. Primary outcome was incidence of cesarean delivery. Maternal and neonatal outcomes were compared secondarily. Statistical analysis was done by intention-to-treat.
Seventy-eight nulliparous women were assigned randomly. All of the women had epidural anesthesia. Maternal demographics were not significantly different. The incidence of cesarean delivery was 19.5% (n = 8/41 deliveries) in the extended labor group and 43.2% (n = 16/37 deliveries) in the usual labor group (relative risk, 0.45; 95% confidence interval, 0.22-0.93). The number needed-to-treat to prevent 1 cesarean delivery was 4.2. There were no statistically significant differences in maternal or neonatal morbidity outcomes.
Extending the length of labor in nulliparous women with singleton gestations, epidural anesthesia, and prolonged second stage decreased the incidence of cesarean delivery by slightly more than one-half, compared with usual guidelines. Maternal or neonatal morbidity were not statistically different between the groups; however, our study was underpowered to detect small, but potentially clinical important, differences.
自 19 世纪以来，人们提出了第二产程管理指南，这些指南主要是基于专家意见制定的。目前，关于第二产程延长与母婴结局的差异，回顾性数据结果不一。没有随机对照试验评估是否延长目前美国妇产科学院推荐的第二产程对母婴结局有益。
本研究旨在评估初产妇第二产程延长时，延长产程是否会影响剖宫产率及母婴结局。
我们对 36 0/7 至 41 6/7 周、单胎妊娠、符合美国妇产科学院第二产程延长定义（硬膜外麻醉下 3 小时或无硬膜外麻醉下 2 小时）的初产妇进行了一项随机对照试验。这些产妇被随机分为延长产程至少 1 小时组或常规产程组，后者通过剖宫产或阴道助产术尽快分娩。排除标准为宫内胎儿死亡、计划剖宫产、年龄<18 岁和疑似严重胎儿畸形。主要结局为剖宫产率。次要结局为母婴结局。采用意向治疗进行统计学分析。
78 名初产妇被随机分配。所有产妇均接受硬膜外麻醉。产妇人口统计学特征无显著差异。延长产程组的剖宫产率为 19.5%（41 例分娩中的 8 例），常规产程组为 43.2%（37 例分娩中的 16 例）（相对风险，0.45；95%置信区间，0.22-0.93）。预防 1 例剖宫产所需的治疗人数为 4.2。两组间产妇或新生儿发病率无统计学差异。
与常规指南相比，在硬膜外麻醉且第二产程延长的初产妇中延长产程可使剖宫产率降低略超过一半。两组间产妇或新生儿发病率无统计学差异；然而，本研究的效力不足以检测到小但可能具有临床意义的差异。
