The Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
The Department of Obstetrics and Gynecology, the Chaim Sheba Medical Center, Ramat-Gan, Israel.
Acta Obstet Gynecol Scand. 2021 Jan;100(1):147-153. doi: 10.1111/aogs.13977. Epub 2020 Sep 26.
We wanted to evaluate whether secundiparas who achieved vaginal birth after cesarean (VBAC) were at an increased risk for obstetric anal sphincter injury (OASI) compared to primiparas who delivered vaginally, with a stratification by the mode of delivery-spontaneous or operative vaginal delivery.
We conducted a retrospective cohort study of primiparous women who delivered by vacuum-assisted delivery between March 2011 and June 2019. Primiparas delivering vaginally and secundiparas undergoing VBAC were compared. The cohort was further stratified into two categories: spontaneous vaginal delivery and operative vaginal delivery.
Overall, 23 822 primiparas who delivered vaginally and 1596 secundiparas who underwent VBAC were analyzed. Operative vaginal delivery was performed in 4561 deliveries. OASI rate did not differ between the VBAC and primipara groups (1.3% vs 1.8%, P = .142). A total of 20 857 women delivered by spontaneous vaginal delivery, among them 1180 (5.7%) women were secundiparas and 19 677 (94.3%) were primiparas. OASI rate was comparable between the secundiparas undergoing VBAC and primiparas delivering vaginally (17 [1.4%] vs 338 [1.7%], P = .436). A total of 4561 women delivered by operative vaginal delivery, among them 416 (9.1%) were secundiparas and 4145 (90.9%) were primiparas. The rate of operative vaginal deliveries was higher among the VBAC group compared with the primipara group (6.1% vs 17.4%, P < .001). However, women undergoing successful VBAC had lower rates of OASI compared with primiparas (3 [0.7%] vs 96 [2.3%]; odds ratio [OR] 0.30, 95% CI 0.09-0.97, P = .032). After multivariate logistic regression including all statistically significant factors, OASI was not associated with VBAC in spontaneous or operative vaginal deliveries (adjusted OR 0.85, 95% CI 0.51-1.40 and 0.39, 95% CI 0.12-1.28, respectively).
Secundiparas undergoing VBAC were not at a higher risk of OASI when compared with primiparas delivering vaginally, either in spontaneous or operative vaginal deliveries. This information might aid when counseling women contemplating a trial of labor after cesarean--to address their concerns regarding the risks and benefits of VBAC.
我们旨在评估与阴道分娩的初产妇相比，行剖宫产术后阴道分娩（VBAC）的经产妇是否有更高的产科肛门括约肌损伤（OASI）风险，分层因素为阴道分娩的方式（自发性或经阴道助产）。
我们对 2011 年 3 月至 2019 年 6 月间行真空辅助分娩的初产妇进行了回顾性队列研究。比较了阴道分娩的初产妇和行 VBAC 的经产妇。该队列进一步分为两类：自发性阴道分娩和经阴道助产。
共有 23822 名初产妇行阴道分娩，1596 名经产妇行 VBAC。4561 例采用经阴道助产分娩。VBAC 组和初产妇组的 OASI 发生率无差异（1.3% vs 1.8%，P=0.142）。共 20857 名妇女经阴道自然分娩，其中 1180 名（5.7%）为经产妇，19677 名（94.3%）为初产妇。VBAC 经产妇与阴道分娩的初产妇 OASI 发生率相当（17 [1.4%] vs 338 [1.7%]，P=0.436）。4561 名妇女行经阴道助产分娩，其中 416 名（9.1%）为经产妇，4145 名（90.9%）为初产妇。VBAC 组经阴道助产分娩的比例高于初产妇组（6.1% vs 17.4%，P<0.001）。然而，与初产妇相比，行 VBAC 成功的妇女 OASI 发生率较低（3 [0.7%] vs 96 [2.3%]；比值比[OR] 0.30，95%CI 0.09-0.97，P=0.032）。在包括所有有统计学意义的因素的多变量逻辑回归后，VBAC 与自发性或经阴道助产分娩的 OASI 无关（调整后的 OR 0.85，95%CI 0.51-1.40 和 0.39，95%CI 0.12-1.28）。
与阴道分娩的初产妇相比，行 VBAC 的经产妇在自发性或经阴道助产分娩时，OASI 的风险并不更高。这一信息可能有助于在为考虑行剖宫产术后试产的妇女提供咨询时，解决她们对 VBAC 风险和益处的担忧。
