Predicting Vaginal Delivery Success: Role of Intrapartum Transperineal Ultrasound Angle of Descent at a Single Center

BACKGROUND Assessment of labor progress via digital vaginal examination is subjective, while intrapartum transperineal ultrasonography is deemed more objective and effective. The angle of descent (AoD) is a reliable intrapartum transperineal ultrasound parameter with minimal inter-observer and intra-observer errors. This study compared intrapartum transperineal ultrasonography with digital vaginal examination in evaluating the angle of descent for vaginal delivery selection in 70 women. MATERIAL AND METHODS This cross-sectional study was conducted at Dr. Mohammad Hoesin Hospital Palembang in Indonesia, using a consecutive sampling method to measure AoD of 70 patients at admission and every 2 h during labor progression. Patients were monitored until childbirth, and outcomes of successful vaginal or cesarean delivery were reported. A diagnostic test determined the optimal AoD for predicting successful vaginal delivery and its predictive value. RESULTS The study included 70 patients with a mean age of 28.29±6.09 years and a body mass index of 30.59±3.49 kg/m². Among them, 29 (41%) had successful vaginal deliveries. Adequate contraction frequency at admission was strongly associated with successful vaginal delivery (P<0.001). The optimal AoD for predicting successful vaginal delivery was 94.5°, with an area under the curve of 0.567 (95% CI 0.425-0.710), sensitivity of 84.2%, specificity of 45.7%, and accuracy of 54.3%. CONCLUSIONS Intrapartum transperineal ultrasonography for measuring AoD can be a valuable adjunct in labor management. Further investigations are needed to validate the optimal AoD in Indonesian pregnant women.