Related Experiment Video
Updated: Mar 15, 2026
Author Spotlight: Advancing Labor Management Through Electromyometrial Imaging for Understanding Uterine Contractions
Published on: May 26, 2023
Automated Measurement of the Angle of Progression in Labor: A Feasibility and Reliability Study
Aly Youssef1, Ginevra Salsi, Elisa Montaguti
1Department of Obstetrics and Gynecology, Sant'Orsola-Malpighi University Hospital, University of Bologna, Bologna, Italy.
Objectives:
The aim of this paper was to assess the feasibility and reliability of a new automated method for the measurement of the angle of progression (AoP) in labor.
Methods:
AoP was assessed using two-dimensional transperineal ultrasound by two operators in 52 women in active labor to evaluate intra- and interobserver reproducibility. The intermethod agreement between automated and manual techniques was analyzed by means of the intraclass correlation coefficient and Bland-Altman method.
Results:
Automated measurements were feasible in all cases. Automated assessments correctly depicted the pubic symphysis and fetal head in 133 (85.3%) out of 156 on first assessments and in all 156 after repeating measurements once in case of incorrect first evaluation. The automated technique showed good intra- and interobserver reproducibility and very good agreement with the manual technique. AoP measured by the automated method were significantly wider than those done by the manual technique (119 ± 20° vs. 130 ± 20°, p = 0.005).
Conclusions:
Automated assessment AoP is feasible and reproducible. However, measurements performed by the automated software are significantly different from those resulting from the previously published manual technique. In the light of our data, the automated technique does not seem ready yet for clinical use, and the AoP should be exclusively measured by the previously suggested manual technique.
