Automated Angle of Progression and Fetal Head Direction During Labor
Authors:
Srinivas Kudavelly, MS (Samsung R&D Institute India, Bangalore, Medical Imaging Group, Health and Medical Equipment)
Shubham Chechani (Samsung R&D Institute India, Bangalore, Medical Imaging Group, Health and Medical Equipment)
GA Ramaraju, MD (Krishna IVF Clinic, Visakhapatnam)
Nitin Singhal (Samsung R&D Institute India, Bangalore, Medical Imaging Group, Health and Medical Equipment)
Presenter:
Srinivas Kudavelly, MS (Samsung R&D Institute India, Bangalore, Medical Imaging Group, Health and Medical Equipment)
Date and Time: April 10, 2019, 12:36 pm–12:43 pm
2019 Scientific Program
Abstract
This study investigates the accuracy of an automated method for measuring the angle of progression (AoP) and fetal head direction (FHD) during the second stage of labor using transperineum ultrasound. We aimed to evaluate the effectiveness of the automated technique in comparison to manual measurements. Our results show high reproducibility and strong correlation between the two methods, confirming the clinical utility of automation in obstetric imaging.
Introduction
The angle of progression (AoP) and fetal head direction (FHD) are critical parameters during labor that assist clinicians in assessing fetal descent and rotation. Traditional manual methods for these measurements can be time-consuming and subject to operator-dependent variation. Recent advancements in ultrasound technology, including automated quantification methods, offer the potential for more consistent and efficient measurements. This study evaluates the effectiveness of an automated method using Samsung Medison HS40 with CA2–8 probe in measuring AoP and FHD during labor.
Objectives
– Assess the accuracy of an automated method for AoP and FHD quantification during the second stage of labor.
– Compare automated measurements with manual measurements using transperineum ultrasound.
– Evaluate the clinical applicability of the automated method in line with ISUOG intrapartum ultrasound guidelines.
Methods
Study Design:
This was a prospective observational study involving 50 subjects in active labor. All subjects underwent a series of transperineum ultrasound scans to measure AoP and FHD.
Instrumentation:
The Samsung Medison HS40 ultrasound machine, equipped with a CA2–8 probe, was used for both manual and automated measurements of AoP and FHD.
Measurement Process:
– Angle of Progression (AoP): The angle between the long axis of the pubic symphysis and a line from the lowest edge of the pubis tangentially to the upper segment of the fetal skull.
– Fetal Head Direction (FHD): The angle between the longest axis of the fetal head and the long axis of the pubic symphysis.
Results
Out of 297 images analyzed:
– Automated measurements were successful in 269 images (90.5%).
– AoP measured by the automated method strongly correlated with manual measurements (mean 131.5 ± 200 vs 131.7 ± 210, p = 0.55).
– Pearson correlation coefficient for AoP was 0.94.
– Mean absolute error difference: 3.360 ± 3.670.
– The automated method successfully detected dynamic changes in FHD in all images, recognizing the progression from downward to horizontal to upward.
Discussion
The automated technique demonstrated high reproducibility and accuracy when compared to manual methods, with minimal deviation between measurements. The strong correlation (Pearson coefficient of 0.94) supports the reliability of the automated system. Our findings suggest that automated quantification of AoP and FHD can significantly enhance clinical workflow by reducing the manual workload and improving measurement consistency.
Conclusion
Automated measurements of AoP and FHD using the Samsung Medison HS40 ultrasound system were found to be accurate and reliable, showing strong agreement with manual measurements. This method can be seamlessly integrated into clinical practice, aligning with ISUOG intrapartum ultrasound guidelines, and could improve the assessment of labor progression.
Publication Information
First Published: June 24, 2019
DOI: 10.1002/jum.15027
Volume 38, Issue S1 – Special Issue: Official Proceedings of the 2019 AIUM Convention, April 6‐10, Orlando, FL