背景:剖腹产(剖腹产)率在全球范围内上升,重复剖腹产与产妇发病率增加有关。剖腹产后试产(TOLAC)是减少剖腹产复发的一种方法。然而,关于剖宫产瘢痕对TOLAC产程影响的研究有限,考虑通过剖腹产终止劳动和选择偏差。本研究旨在探讨剖宫产瘢痕对TOLAC参与者产程的影响。考虑潜在的混杂因素和偏见。
方法:这项回顾性队列研究包括2012年至2021年在日本一个中心尝试阴道分娩的2,964名妇女。该研究将参与者分为TOLAC(n=187)和非TOLAC(n=2,777)组。倾向得分是根据14个可能影响产程的因素计算的,并应用治疗加权逆概率(IPTW)。Cox比例风险回归分析劳动力持续时间的估计风险比(HR),有和没有IPTW调整。敏感性分析使用倾向评分匹配,自举,和间隔审查以解决潜在的偏见,包括报告的分娩开始中的回忆偏差。
结果:与非TOLAC组相比,TOLAC组的分娩时间未调整HR为0.83(95%CI:0.70-0.98,P=0.027),表明TOLAC组的产程较长。在使用IPTW调整混杂因素后,HR为0.98(95%CI:0.74-1.30,P=0.91),提示两组之间的产程时间没有显着差异。使用倾向评分匹配的敏感性分析,自举,和间隔审查产生了一致的结果。这些发现表明,TOLAC与更长的分娩时间之间的明显关联是由于混杂因素而不是TOLAC本身。
结论:在调整了混杂因素并解决了潜在的偏见之后,剖宫产瘢痕对TOLAC参与者的产程影响有限。产妇和胎儿的特征可能对分娩时间有更大的影响。
BACKGROUND: Cesarean section (C-section) rates are increasing globally, and repeated C-sections are associated with increased maternal morbidity. Trial of labor after C-section (TOLAC) is an approach to reduce the recurrence of C-sections. However, limited research exists on the impact of cesarean scars on labor duration in TOLAC, considering the termination of labor through C-section and selection bias. This study aimed to investigate the impact of cesarean scars on labor duration in TOLAC participants, accounting for potential confounding factors and biases.
METHODS: This retrospective cohort study included 2,964 women who attempted vaginal birth at a single center in Japan from 2012 to 2021. The study categorized participants into TOLAC (n = 187) and non-TOLAC (n = 2,777) groups. Propensity scores were calculated based on 14 factors that could influence labor duration, and inverse probability of treatment weighting (IPTW) was applied. Cox proportional hazards regression analysis estimated hazard ratios (HRs) for labor duration, with and without IPTW adjustment. Sensitivity analyses used propensity score matching, bootstrapping, and interval censoring to address potential biases, including recall bias in the reported onset of labor.
RESULTS: The unadjusted HR for labor duration in the TOLAC group compared to the non-TOLAC group was 0.83 (95% CI: 0.70-0.98, P = 0.027), indicating a longer labor duration in the TOLAC group. After adjusting for confounding factors using IPTW, the HR was 0.98 (95% CI: 0.74-1.30, P = 0.91), suggesting no significant difference in labor duration between the groups. Sensitivity analyses using propensity score matching, bootstrapping, and interval censoring yielded consistent results. These findings suggested that the apparent association between TOLAC and longer labor duration was because of confounding factors rather than TOLAC itself.
CONCLUSIONS: After adjusting for confounding factors and addressing potential biases, cesarean scars had a limited impact on labor duration in TOLAC participants. Maternal and fetal characteristics may have a more substantial influence on labor duration.