The application study of the virtual touch tissue quantification technique in predicting the outcome of labor induction

Objective To estimate cervical stiffness during late pregnancy with virtual touch tissue quantification technique(VTQ) and investigate the value of predicting the outcome of labor induction. Methods Cervical length in pregnancy women at 35-41 weeks′gestation was measured through perineum ultrasound examination before labor induction, and then VTQ was applied to measure shear wave velocity(SWV)values in region of interest(ROI), the maximum, minimum and average of SWV values were obtained from multiple SWV measurement under the VTQ mode. The outcomes of labor induction were tracked and Bishop scores were recorded, vaginal delivery and cesarean delivery groups were compared using Student′s t-test for continuous variables. ROC curve was plotted to analyze the correlation between parameters and the outcome of labor induction and to determine the most accurate SWV value and cut-off value for diagnosis. Univariate and multivariate logistic regression analysis were used to determine which of the following parameters were significant predictors of the outcome of labor induction. Results The SWV mix, SWV max and SWV mean of vaginal delivery and cesarean section were (0.92±0.13)m/s, (1.37±0.14)m/s, (1.13±0.10)m/s and (1.03±0.13)m/s, (1.74±0.42)m/s, (1.36±0.11)m/s, respectively, there were significant differences between vaginal delivery and cesarean section(all P<0.05). Based on ROC curve analysis, the SWV mean value in cervix was the best value for predicting the outcome of labor induction. The cut-off value of SWV mean value was 1.23 m/s, the sensitivity, specificity and Youden index were 93.8%, 83.4%, 0.77, respectively. The SWV value and cervical length were closely correlated to the outcome of labor induction, especially the SWV value according to multivariate logistic analysis. Conclusions VTQ can assess the cervical stiffness with SWV values during pregnancy, and it may have an application value of predicting the outcome of labor induction. Key words: Virtual touch tissue quantification; Shear wave velocity; Pregnancy; Cervix; The outcome of labor induction