Risk factors for unintended uterine incision extension in emergency cesarean deliveries: A retrospective case–control study

OBJECTIVE: To identify risk factors for unintended uterine incision extension (UUIE) during emergency cesarean deliveries. METHODS: We conducted a single-center retrospective case-control study including women who underwent singleton emergency low transverse cesarean delivery between February 2020 and January 2022. Multivariable logistic regression was used to identify independent factors associated with UUIE and to calculate adjusted odds ratios with 95% confidence intervals (CIs). RESULTS: The present study included 2676 women, of whom 270 (270/2676, 10.1%) experienced UUIE. Oligohydramnios (adjusted odds ratio [aOR] 2.74, 95% CI 1.70-4.42; P < 0.001), bladder flap dissection (aOR 1.47, 95% CI 1.14-1.90; P = 0.003), and second-stage arrest (aOR 2.35, 95% CI 1.72-3.22; P < 0.001) were independently associated with increased odds of UUIE. Preterm delivery at 34-36 weeks was associated with decreased odds compared with term delivery (aOR 0.57, 95% CI 0.34-0.96; P = 0.034), whereas delivery before 34 weeks showed a nonsignificant trend (aOR 0.42, 95% CI 0.18-1.01; P = 0.052). Cesarean delivery without a trial of labor was associated with lower odds compared with spontaneous (aOR 5.71, 95% CI 4.23-7.70; P < 0.001) or induced labor (aOR 4.60, 95% CI 3.17-6.68; P < 0.001). CONCLUSIONS: Unintended uterine incision extension is a common complication in emergency cesarean deliveries. Second-stage arrest, oligohydramnios, and bladder flap dissection increased odds of UUIE, whereas preterm delivery and cesarean delivery without a trial of labor were associated with lower odds of UUIE.