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Recording available 2/16-5/2
Recording available 2/16-5/2
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Abstract Award
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Poster Session 1

Category: Intrapartum Fetal Assessment

Poster Session 1

(284) Angle of Progression velocity as a sonographic marker for operative delivery due to labor arrest

Wednesday, February 11, 2026
10:30 AM - 12:00 PM  

    Submitting Author and Presenting Author(s)

  • Mai Shiber, MD (she/her/hers)

    Helen Schneider Hospital for Women, Rabin Medical Center
    Rabin Medical Center – Beilinson Hospital, HaMerkaz, Israel

    • Coauthor(s)

  • YG

    Yossi Geron, MD

    Helen Schneider Hospital for Women, Rabin Medical Center
    Petah Tikva, HaMerkaz, Israel

  • NB

    Nati Bor, MD

    Resident
    Helen Schneider Hospital for Women, Rabin Medical Center, Petah Tikva, Israel
    Petah Tikva, HaMerkaz, Israel

  • Miriam Lopian, MD

    Senior Doctor
    Helen Schneider Hospital for Women, Rabin Medical Center
    Petah Tikva, HaMerkaz, Israel

  • Yinon Gilboa, MD

    Professor
    Helen Schneider Hospital for Women, Rabin Medical Center
    Petah Tikva, HaMerkaz, Israel

  • EH

    Eran Hadar, MD, PhD

    Rabin Medical Center
    Petach Tikva, HaMerkaz, Israel

  • Natav Hendin, MD

    Rabin Medical Center
    Petah Tikva, HaMerkaz, Israel

Objective:

To evaluate whether the rate of Angle of Progression (AoP) advancement, measured via serial transperineal ultrasound during the second stage of labor, is associated with mode of delivery – specifically the risk of operative vaginal or cesarean delivery due to prolonged second stage (PSS) or arrest of descent compared to spontaneous vaginal delivery.

Study Design:

This retrospective cohort study included 154 women who delivered at a single tertiary center (May 2023 - July 2025) and underwent ≥ 2 AoP measurements during the second stage of labor. Patients were categorized by mode of delivery: spontaneous vaginal delivery (n=85) vs. operative delivery (vacuum or cesarean) due to prolonged second stage or arrest of descent (n=69). Cases of operative delivery for non-reassuring fetal heart rate were excluded. AoP velocity (°/min) was calculated and compared between groups. Multivariate logistic regression assessed associations between sonographic measures and mode of delivery, adjusted for parity, fetal head position, station, and time from full dilation to first AoP.

Results:

Operative delivery was associated with significantly lower AoP velocity (0.18 ± 0.15 vs. 0.27 ± 0.28 °/min, p </span>< 0.05).  In adjusted multivariable analysis, faster AoP velocity remained independently associated with reduced odds of operative delivery (adjusted OR 0.08; 95% CI 0.01–0.79; p </span>< 0.05). Neonatal outcomes, including NICU admission, cord pH and low Apgar (< 7 at 5 minutes), did not differ significantly between groups. The operative delivery group had higher postpartum hemorrhage (22.9% vs. 5.6%; p</span>< 0.05) and longer postpartum stay (4.24 vs. 3.65 days; p = < 0.05).

Conclusion:

Slower AoP velocity is a strong marker for operative delivery due to labor arrest. In contrast,  faster progression of AoP during second-stage labor is independently associated with spontaneous vaginal delivery. Serial AoP assessment may provide a real-time, objective tool to support intrapartum decision-making and anticipate abnormal labor progression.