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CME Credit Offered
CME Credit Offered
Abstract Award
Abstract Award
Recording available 2/16-5/2
Recording available 2/16-5/2
AIUM Credit
AIUM Credit
Foundation Awardee
Foundation Awardee
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Abstract Award
Abstract Award
Foundation Awardee
Foundation Awardee

Poster Session 3

Category: Operative Obstetrics

Poster Session 3

(703) Uterine Rupture: Comparison of Intact Versus Scarred Uterus

Thursday, February 12, 2026
10:30 AM - 12:00 PM  
Objective:
Rupture of an unscarred uterus is uncommon with data limited to case reports and series. The objective of this study was to report on perinatal outcomes in cases of uterine rupture in an unscarred uterus when compared to a scarred uterus.

Study Design:
This is a retrospective cohort study at a single institution including all patients with a diagnosis of uterine rupture between May 2009 and November 2024. Perinatal outcomes were compared between patients who experienced a uterine rupture with a history of prior uterine surgery to those with an unscarred uterus.  Of note, at this institution during the study period trial of labor after cesarean is not recommended without a known history of one uncomplicated prior transverse cesarean, and oxytocin is not routinely administered in the setting of prior uterine scar and a non-anomalous live fetus.

Results:
Out of 187,352 deliveries, there were 95 (0.51 per 1,000) uterine ruptures. The rate of uterine rupture in the setting of prior uterine surgery was 57/36,712 (1per 625).  The rate of uterine rupture of an unscarred uterus was 38/150,640 (1 per 4000). Patients with an unscarred uterus were older, more likely to be Hispanic and nulliparous, delivered at later gestational ages, and more commonly underwent induction (all p< 0.05) (Table 1). The median Maximum cervical dilation of patients with an unscarred uterus was 8.5 (6-10) compared to 3.5 (1-6) in patients with a scarred uterus (p< 0.001). Their rupture was more likely to occur in the second stage of labor (39% vs 18%, p = 0.017) and in the posterior aspect of the uterus (21% vs 2%, p=0.002). They more often required blood transfusion (79% vs 58%, p = 0.026) and a hysterectomy (48% vs 23%, p = 0.021). Fetal weight was higher in the unscarred cohort (3663 (3304-3993g) vs 3220 (2595-3688g), p< 0.001) and base excess < -12 was more common (63% vs 35%, p = 0.006) (Table 2).

Conclusion:
Uterine rupture with unscarred uterus, while rare, is more often associated with adverse maternal and neonatal outcomes including transfusion, hysterectomy, and elevated base excess.