Role of cervical sliding sign in predicting preterm delivery in pregnancies complicated with preterm premature rupture of membranes

Objective To investigate the effect of cervical sliding sign (CSS) to predict preterm delivery in patients with premature rupture of membranes. Methods This prospective cohort study included 88 pregnant women between 24(0/7) and 36(6/7) weeks of gestation who were complicated with preterm premature rupture of membranes (PPROM) between June 2020 and January 2022. We measured the cervical length (CL) and applied pressure to the anterior fornix of the cervix with the transvaginal probe to investigate the CSS, which is defined as the sliding of the anterior lip of the cervix on the posterior lip. Results The time between PPROM and delivery was significantly shorter in the CSS+ group (P < 0.001). Receiver operating characteristic curve analysis was performed for CSS with regard to predicting delivery within 7 days following PPROM (area under the curve, 0.749 [95% confidence interval, 0.642-0.857], P < 0.001). On logistic regression analysis, CL <25 mm increased the predictive accuracy of delivery within 7 days following PPROM 1.91-fold, and CSS increased the predictive accuracy of delivery within 7 days following PPROM 10.71-fold. Conclusion CSS is an effective sonographic marker in predicting preterm delivery and provides better information of oncoming preterm delivery in patients with PPROM than CL measurement.