Accuracy of the Anterior Uterocervical Angle in Predicting the Transvaginal Cerclage Failure to Prevent Spontaneous Preterm Birth Relative to the Cervical Length in Sonography

Background & Objective: Spontaneous preterm birth (SPB) occurs in about 10 to 12 percentage of pregnancies and causes many complications and mortality during pregnancy periods (1). The aim of this study was to determine the evaluation of uterocervical angle compared to cervical length as a sonographic method in predicting preterm delivery for patients who were undergoing the transvaginal cerclage. Materials & Methods: The present study was performed on 91 pregnant women who were candidates for cerclage in Zabol, Iran, 2019-2020. In this study, about 16.48 percentage of births were preterm and 27.47 percentage were post-term. During the study, routine cervical evaluation was performed by post-cerclage ultrasound and transvaginal ultrasound was performed in all patients one week after cerclage. Additional evaluation with transvaginal ultrasound was performed at intervals determined by the treating physicians with final ultrasound evaluation of the cervix up to 28 weeks of gestation. Finally, the obtained data were entered into SPSS 22 and statistically analyzed using t-test, Chi-square and Fisher's exact test. Results: The results of the present study showed that considering the existing thresholds (95 and 105) for the anterior uterosacral angle and the threshold 25 for the cervical length index, all these indices were included 100% sensitive. Conclusion: This sensitivity in the case of UCA higher than 95°C was about 80%, but the disadvantage of these indicators was their low specificity, so that these indicators were different ranging from 30% in the case of (UCA 105) to 7.15% in the case of (UCA 95).