Abstract: Objective　To investigate the labor time in vaginal birth after cesarean section（VBAC） so as to get definite evaluating and monitoring points of VBAC.Methods　75 pregnant women who underwent trial of labor after cesarean（TOLAC） in Beijing Obstetrics and Gynecology Hospital,Capital Medical University from January 2012 to June 2015 were selected.Among them,70 cases（VBAC,93.3%） had successful vaginal delivery,5 cases（6.7%） with unsuccessful vaginal trial production underwent cesarean section again.According to the timing of previous cesarean section,70 pregnant women with VBAC were divided into cesarean section after vaginal trial of production group（n=23） and elective cesarean section group（n=47）,and their stages of labor were recorded.Results　The average age and parity of patients in elective cesarean section group were respectively younger and less than those of patients in cesarean section after vaginal trial of production group（P<0.05）;the comparison of gestational age,times of pregnancy,pre-pregnancy BMI,prenatal BMI,thickness of lower uterine segment and premature rupture of membrane through ultrasonic testing,and proportion of gestational diabetes and pregnancy complicated with hypertension among pregnant women in two groups was not significantly different（P>0.05）.There was no significant difference in times of the first stage of labor,the second stage of labor and total stage of labor among pregnant women with no history of vaginal delivery in two groups（P>0.05）;there was no significant difference in times of the first stage of labor,the second stage of labor and total stage of labor among term delivery women with no history of vaginal delivery in two groups（P>0.05）.The amount of postpartum hemorrhage,neonatal weight,neonatal Apgar score,and the proportion of puerperal infection,fetal distress,amniotic fluid Ⅲ,neonatal morbidity,forceps delivery and maternal postpartum hemorrhage among pregnant women in two groups were not significantly different（P>0.05）.Conclusion　There is no effect of VBAC pregnant women with or without trial production in previous delivery on labor time and pregnancy outcome,the persistent progress of labor time is key to the successful vaginal delivery.Risks should be fully evaluated again for patients with labor stagnation or related manifestations,so as to reduce the risk of uterine rupture after cesarean section.

Key words: Vaginal birth after cesarean, Labor,obstetric, Pregnancy outcome

摘要： 目的　了解剖宫产术后阴道分娩（VBAC）的产程时限，以明确VBAC的评估和监测要点。方法　选取2012年1月—2015年6月到首都医科大学附属北京妇产医院就诊的剖宫产术后阴道试产（TOLAC）产妇75例，其中经阴道成功分娩70例（VBAC，93.3%），经阴道试产失败后再次行剖宫产5例（6.7%）。根据前次剖宫产时机，将70例VBAC产妇分为试产后剖宫产组（n=23）和择期剖宫产组（n=47），并记录其产程。结果　择期剖宫产组患者的平均年龄低于试产后剖宫产组，产次少于试产后剖宫产组，差异有统计学意义（P<0.05）；两组产妇的分娩孕周、孕次、孕前BMI、产前BMI、超声检测子宫下段厚度及胎膜早破、合并糖尿病、合并妊娠高血压比例比较，差异无统计学意义（P>0.05）。两组无阴道分娩史产妇的第一产程、第二产程及总产程时间比较，差异无统计学意义（P>0.05）；两组无阴道分娩史足月分娩产妇的第一产程、第二产程及总产程时间比较，差异亦无统计学意义（P>0.05）。两组产妇的产后出血量、新生儿体质量、新生儿阿氏评分及产褥感染、胎儿窘迫、羊水Ⅲ度、新生儿患病、产钳助产、产后出血比例比较，差异均无统计学意义（P>0.05）。结论　前次分娩是否试产对VBAC产妇的产程时限和妊娠结局无影响，产程的持续进展是阴道成功分娩的关键，对于产程停滞或有相关表现患者，应再次充分评估风险，以降低剖宫产术后子宫破裂风险。

关键词: 剖宫产后阴道分娩, 分娩, 产道, 妊娠结局