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Am J Perinatol 2026; 43(01): 023-031
DOI: 10.1055/a-2586-3568
Original Article

Analysis of Hysterotomy Extension at Unscheduled Cesarean Delivery

Authors

  • Jason G. Bunn

    1   Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas
    2   Parkland Hospital, Dallas, Texas

  • Albert Tang

    1   Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas

  • Kristen Warncke

    1   Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas
    2   Parkland Hospital, Dallas, Texas

  • Saron Gilazgi

    1   Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas

  • Donald D. Mcintire

    1   Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas

  • David B. Nelson

    1   Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas
    2   Parkland Hospital, Dallas, Texas

  • Catherine Y. Spong

    1   Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas
    2   Parkland Hospital, Dallas, Texas

  • J. Seth Hawkins

    1   Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas
    2   Parkland Hospital, Dallas, Texas

Funding None.
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Abstract

Objective

This study aimed to determine if the rate of hysterotomy extensions increases with increasing cervical dilation in unscheduled cesarean deliveries, and to develop a measure of the severity of hysterotomy extension for quantifying morbidity.

Study Design

This is a retrospective study of unscheduled cesarean deliveries relating to labor dystocia and/or nonreassuring tracings from January 1, 2021, to December 31, 2021. Severe extension was defined as bilateral or adjacent to a structure such as the uterine artery, broad ligament, or cervix, and was compared with uterine artery extensions alone.

Results

There were 990 unscheduled cesarean deliveries included. Extensions (n = 233) significantly increased with increasing cervical dilation (p < 0.0001), complicating more than 30 and 50% at 6 and 10 cm of cervical dilation, respectively. Apart from this trend, a logistic regression analysis indicated cervical dilation was an independent risk factor for extension. Transfusions of at least 2 units of blood were five times (26 vs. 5%) more likely for patients with severe extensions than no extension (p < 0.0001).

Conclusion

Hysterotomy extensions significantly increase with increasing cervical dilation, and cervical dilation is an independent risk factor for extension. A composite measure of severity accounts for different types of extension when quantifying morbidity, but uterine artery extension is the primary driver of maternal morbidity in cases without hysterectomy.

Key Points

  • We report higher than previously published rates of extension, in our study of unscheduled cesareans.

  • Extension rates rise with cervical dilation—33% at 6 cm, over 50% at 10 cm.

  • Cervical dilation is an independent risk factor for extension.

  • Severe extensions were fivefold more likely to be transfused two units than no extension.

  • The composite measure for severity was driven by uterine artery extensions.

Keywords

cesarean morbidity - hysterotomy extension - labor dystocia - second stage arrest

Supplementary Material



Publication History

Received: 01 January 2025

Accepted: 13 April 2025

Article published online:
06 May 2025

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