Objective: To assess the angle of progression (AOP) cervical length and bishop score before onset of labor as a tool in the prediction of normal delivery.

Materials and Methods: The present study was a prospective study of singleton cephalic term pregnant women. AOP was measured at more than 38 weeks of gestation by transperineal ultrasound examinations before the onset of labor. Pelvic examination for bishop score and transvaginal ultrasound for cervical length were obtained at the same time. All women were followed until delivery to evaluate the mode of delivery.

Results: One hundred eighty-six patients were included in the analysis. One hundred forty-four (77.4%) women had vaginal delivery and median AOP for the study group was 100 degrees. The adjusted risk ratio (aRR) of vaginal delivery in those patients who had an AOP of more than 100 degree was 1.48 (95% CI 0.71 to 3.07; p=0.292). A cervical length (CL) of more than 25.0 mm. had decreased chance of vaginal delivery at aRR 0.71 (95% CI 0.35 to 1.45; p=0.354). While Bishop score (BS) of more than 5 had increased chance of vaginal delivery at aRR 1.14 (95% CI 0.51 to 2.55; p=0.737). However, a statistically significant correlation was not found in AOP, cervical length, and Bishop score at before onset of labor for the prediction vaginal delivery.

Conclusion: A larger angle of AOP of more than 100 degrees at term, cervical length of less than 25 mm. and bishop score of more than 5 before onset of labor were not statistically significant to predict vaginal delivery.

Keywords: Angle of progression, Bishop score, Cervical length

Received 14 Jun 2019 | Revised 3 Sep 2019 | Accepted 10 Sep 2019