Diagnostic accuracy of pre-induction cervical elastography, volume, length, and uterocervical angle for the prediction of successful induction of labor with dinoprostone.

PURPOSE: The study's aim is to define among a group of ultrasonographic cervical measurements a candidate parameter predictive of successful of induction of labor in term pregnancies with unfavorable cervix.

METHODS: This prospective observational study included 141 pregnant women at term with an unfavorable cervix (Bishop score ≤ 6). All patients underwent clinical and ultrasonographic cervical evaluation before dinoprostone induction. Pre-induction cervical assessments included the Bishop score, cervical length, cervical volume, uterocervical angle, and cervical elastographic parameters. Vaginal delivery (VD) was accepted as successful dinoprostone induction. Multivariate logistic regression was conducted to identify the potential risk factors significantly associated with CS while controlling for possible confounding variables.

RESULTS: The vaginal delivery rate was 74% (n = 93) and the cesarean section (CS) rate was 26% (n = 32). Sixteen patients who had a cesarean section due to fetal distress before the active phase of labor were excluded from the study. The mean induction-to-delivery interval was 1176.1 ± 352 (540-2150) for VD and 1359.4 ± 318.4 (780-2020) for CS (p = 0.01). Bishop score was lower in women with cesarean section (p = 0.002). When both groups were compared in terms of delivery type, no difference was found between cervical elastography values, cervical volume, cervical length, and uterocervical angle measurements. Multivariable logistic regression model failed to show significant differences between cervical elastography values, cervical volume, cervical length, and uterocervical angle measurements.

CONCLUSION: Cervical length, cervical elastography, cervical volume, and uterocervical angle measurements did not provide a clinically useful prediction of outcomes following labor induction in our study group with unfavorable cervix. Cervical length measurements significantly predicted the time interval from induction to delivery.