Influence of Utero-cervical Angle and Cervical Length on Labor Induction

Abstract

Background: Successful labor induction is clearly related to the state of the cervix. The utero-cervical angle and cervical length represent novel ultrasonographic markers. Aim: To assess the relationship between utero-cervical angle and cervical length and satisfactory response to labor induction. Methods: Prospective cohort study was conducted in Al-Elwyia Maternity Teaching Hospital for a period of six months; 100 cases were enrolled in the study, and a pre-labor induction measurement of utero-cervical angle and cervical length using transvaginal ultrasound scanning was followed up till the end of labor to estimate the rate of success of induction of labor. Results: 65 patients had successful induction of labor and 35 failed to do so. No differences were found in demographic data and previous obstetric history. Short cervical length and wide utero-cervical angle were found in successful induction of labor. A significant negative correlation was found between utero-cervical angle and labor duration. At the cutoff point of 97.5 degrees of utero-cervical angle, the sensitivity was 83.12%, specificity was 71.4%, positive predictive value was 84.38%, negative predictive value was 69.45% and the accuracy was 88%. At a cutoff point of less than 29.5 mm of cervical length, the sensitivity was 92.3%, specificity was 80%, positive predictive value was 89.55%, negative predictive value was 84.84% and the accuracy was 88%. Conclusion: Utero-cervical angle and cervical length may be independent predictors of successful induction of labor.