Tan P C, Vallikkannu N, Suguna S, Quek K F, Hassan J
Department of Obstetrics and Gynecology, University of Malaya, Kuala Lumpur, and Likas Hospital, Kota Kinabalu, Malaysia.
Ultrasound Obstet Gynecol. 2007 May;29(5):568-73. doi: 10.1002/uog.4018.
To compare transvaginal sonography for cervical length measurement and digital examination for Bishop score assessment in women undergoing labor induction at term, to assess their tolerability (in terms of pain) and ability to predict need for Cesarean delivery.
A prospective study was performed on 249 women admitted for labor induction. Cervical length was measured using transvaginal ultrasound examination. A 10-point visual analog scale (VAS) for procedure-related pain was obtained. Bishop score was determined just before labor induction and another pain score was obtained. Delivery outcome was recorded. Analyses were by t-test, Fisher's exact test, receiver-operating characteristics (ROC) curves and multivariate logistic regression.
Transvaginal sonography was significantly less painful than digital examination for Bishop score assessment (mean difference in VAS score 3.46; P<0.001). Analyses of the ROC curves for cervical length and Bishop score indicated that both were predictors of Cesarean delivery (area under the curve 0.611 vs. 0.607; P=0.012 vs. P=0.015, respectively) with optimal cut-offs for predicting Cesarean delivery of >20 mm for cervical length and Bishop score<or=5. Cervical length had superior sensitivity (80% vs. 64%) and marginally better positive (30% vs. 27%) and negative (89% vs. 83%) predictive values. Multivariate logistic regression analysis revealed that only nulliparity (adjusted odds ratio (AOR) 4.1; 95% CI, 2.1-8.1; P<0.001) and transvaginal sonographic cervical length>20 mm (AOR 3.4; 95% CI, 1.4-8.1; P=0.006) were independent predictors of Cesarean delivery.
Transvaginal sonography for cervical length measurement is better tolerated than digital examination for Bishop score assessment. Both cervical length and Bishop score are useful predictors of the need for Cesarean delivery following labor induction. A cervical length>20 mm at labor induction at term is an independent predictor of Cesarean delivery.
比较足月引产女性经阴道超声测量宫颈长度和指诊评估Bishop评分的情况，评估其耐受性（疼痛方面）以及预测剖宫产需求的能力。
对249名入院引产的女性进行前瞻性研究。采用经阴道超声检查测量宫颈长度。获取与操作相关疼痛的10分视觉模拟量表（VAS）评分。在引产即将开始前确定Bishop评分，并获取另一个疼痛评分。记录分娩结局。采用t检验、Fisher精确检验、受试者操作特征（ROC）曲线和多因素逻辑回归进行分析。
经阴道超声评估Bishop评分时的疼痛程度明显低于指诊（VAS评分平均差异为3.46；P<0.001）。对宫颈长度和Bishop评分的ROC曲线分析表明，二者均为剖宫产的预测指标（曲线下面积分别为0.611和0.607；P分别为0.012和0.015），预测剖宫产的最佳截断值为宫颈长度>20mm和Bishop评分≤5。宫颈长度具有更高的敏感性（80%对64%），阳性预测值略高（30%对27%），阴性预测值也略高（89%对83%）。多因素逻辑回归分析显示，只有初产（调整优势比[AOR]4.1；95%可信区间，2.1 - 8.1；P<0.001）和经阴道超声测量宫颈长度>20mm（AOR 3.4；95%可信区间，1.4 - 8.1；P = 0.006）是剖宫产的独立预测因素。
经阴道超声测量宫颈长度比指诊评估Bishop评分的耐受性更好。宫颈长度和Bishop评分都是引产术后剖宫产需求的有用预测指标。足月引产时宫颈长度>20mm是剖宫产的独立预测因素。
