Objective: To evaluate the sensitivity and specificity of a transperineal ultrasound technique for assessment of the angle of
progression during labor. Methods: We carried out a diagnostic test study. Transperineal ultrasound in 375 pregnant women with an
uncomplicated pregnancy, singleton, crown, a full month in the second stage of labor in Hung Vuong Hospital. Results: The angle of
progression was more significant than or equal to 120 degrees on the transperineal ultrasound with sensitivity (96.5%), specificity
(17.5%), PPV of 0.86, NPV of 0.47. The vaginal birth rate of ≥ 120 degrees is 96.2%. Correlation between transperineal
ultrasonography on the pelvic floor of the uterus, mononuclear maturation, maturation, and crown with birth outcomes: progressive
angle ≥ 120 degrees, has 1.66 times higher in vaginal delivery than the angle of progression was <120 degree, 95% CI [1.09 - 2.49].
The optimal progressive angle was 152 degrees with sensitivity, specificity for vaginal delivery was 50%, and 87.7% (Youden score).
Conclusion: Transperineal ultrasound can help clinicians to evaluate the fetus head position during labor. More research is needed
on this issue in the future.
Keywords: angle of progression, transperineal ultrasound, the second stage of labor, diagnostic test study.