剖宫产术后再次妊娠阴道试产影响因素探讨

Influencing factors for trial of labor after cesarean section in women becoming pregnant again

摘要:

目的 探讨剖宫产术后再次妊娠阴道分娩（vaginal birth after cesarean section，VBAC）成功率的影响因素，指导剖宫产术后再次妊娠阴道试产（trial of labor after cesarean，TOLAC）临床决策，提高VBAC成功率，减少不良母婴结局的发生。方法 回顾性分析2020年1月至2022年10月于重庆医科大学附属妇女儿童医院（重庆市妇幼保健院）产科中心TOLAC孕妇共452例，其中VBAC孕妇342例，TOLAC失败孕妇110例，根据最终分娩方式从各随机选取110例孕妇分为VBAC组和TOLAC失败组。采用单因素分析和多因素Logistic回归分析VBAC的影响因素，并比较2组孕产妇的妊娠结局。结果 ①总体VBAC率为75.67%（342/452），TOLAC失败率为24.33%（110/452）。②产前影响因素单因素分析发现，VBAC组与TOLAC失败组孕妇的孕周分别为（38.44±2.13）、（38.96±1.34）周，既往因不良孕产史行引产分别为11.82%、2.80%，存在妊娠合并症为32.73%、20.56%，比较差异有统计学意义（均P<0.05）。入院时宫颈Bishop评分（5.15±1.69、3.71±1.52），既往阴道分娩史（32.73%、20.56%），自然临产（86.36%、17.76%）分别比较，差异也有统计学意义（均P<0.001）。③母婴妊娠结局单因素分析发现，新生儿体质量分别为（3 191.82±489.00）、（3 334.15±375.9） g，产后24 h出血量分别为（408.75±142.31）、（560.85±168.61） mL，VBAC组均低于TOLAC失败组，差异有统计学意义（均P<0.05）。TOLAC失败组中有7例不全子宫破裂。2 组妊娠结局中输血、产褥感染、新生儿5 min Apgar评分的分别比较，差异无统计学意义。无孕产妇及围产儿死亡病例。④多因素Logistic回归分析显示，入院时宫颈Bishop评分（OR=0.122，95%CI=0.010~1.441）、既往阴道分娩史（OR=0.034，95%CI=1.297~715.194）、早产（OR=186.54，95%CI=2.225~15 638.578）及自然临产（OR=52.37，95%CI=8.949~306.517）均是VBAC的影响因素。结论 VBAC的影响因素为孕妇的孕周、既往阴道分娩分娩史、既往因不良孕产史引产、存在妊娠合并症、入院时宫颈Bishop评分、自然临产、早产史。VBAC组产后24 h出血量低于TOLAC失败组。

Abstract:

Objective To investigate the influencing factors for the success rate of vaginal birth after cesarean section（VBAC），to guide clinical decision-making for trial of labor after cesarean section（TOLAC），and to improve the success rate of VBAC and reduce the occurrence of adverse maternal and fetal outcomes.Methods A retrospective analysis was performed for 452 pregnant women who experienced TOLAC in Obstetrics Center of Women and Children’s Hospital of Chongqing Medical University（Chongqing Health Center for Women and Children） from January 2020 to October 2022，among whom 342 experienced VBAC and 110 experienced failed TOLAC. According to the final mode of delivery，110 pregnant women were selected as VBAC group，and 110 were selected as failed TOLAC group. Univariate analysis and multivariate logistic regression analysis were used to investigate the influencing factors for VBAC，and pregnancy outcome was compared between the two groups.Results In this study，the overall VBAC rate was 75.67%（342/452），and the TOLAC failure rate was 24.33%（110/452）. The univariate analysis of prenatal factors showed that there were significant differences between the VBAC group and the failed TOLAC group in gestational age（38.44±2.13 weeks vs. 38.96±1.34 weeks，P<0.05） and the proportion of pregnant women with induction of labor due to the history of abnormal pregnancy（11.82% vs. 2.80%，P<0.05） or pregnancy comorbidities（32.73% vs. 20.56%，P<0.05），and there were also significant differences between the two groups in cervical Bishop score on admission（5.15±1.69 vs. 3.71±1.52，P<0.001），the proportion of women with a history of vaginal delivery（32.73% vs. 20.56%，P<0.001），and the proportion of women with spontaneous delivery（86.36% vs. 17.76%，P<0.001）. The univariate analysis of maternal and infant pregnancy outcomes showed that compared with the failed TOLAC group，the VBAC group had a significantly lower body weight of neonates（3 191.82±489.00 g vs. 3 334.15±375.99 g，P<0.05） and significantly lower blood loss within 24 hours after delivery（408.75±142.31 mL vs. 560.85±168.61 mL，P<0.05）.］There were 7 patients with incomplete uterine rupture in the failed TOLAC group. There were no significant differences between the two groups in blood transfusion，puerperal infection，and 5-minute Apgar score of neonates. There was no death of pregnant and parturient women or perinatal infants. The multivariate logistic regression analysis showed that cervical Bishop score on admission（odds ratio ［OR］=0.122，95%CI： 0.010-1.441），history of vaginal delivery（OR=0.034，95%CI： 1.297-715.194），premature delivery（OR=186.54，95%CI： 2.225-15638.578），and spontaneous labor（OR=52.37，95%CI： 8.949-306.517） were influencing factors for VBAC.Conclusion Gestational weeks，history of vaginal delivery，history of induction of labor due to abnormal pregnancy，pregnancy comorbidities，cervical Bishop score on admission，spontaneous labor，and history of premature delivery are influencing factors for VBAC. The VBAC group has lower blood loss within 24 hours after delivery than the failed TOLAC group.