Ultrasound assessment of maternal risk factors for uterine scar dehiscence in repeat cesarean deliveries: a case-control study from Beirut clinic.

BACKGROUND: With rising cesarean delivery rates, uterine scar complications are becoming more common. Uterine scar dehiscence is often asymptomatic and is detected during repeat cesarean delivery, yet it carries risks of uterine rupture and adverse maternal and neonatal outcomes. Identifying maternal predictors and lower uterine segment (LUS) ultrasound measurements is essential in high-cesarean-rate settings, such as Lebanon. OBJECTIVE: To evaluate maternal and obstetric factors and ultrasonographic LUS measurements associated with uterine scar dehiscence in women undergoing repeat cesarean delivery and to assess neonatal outcomes. METHODS: This retrospective case-control study included 221 women who underwent a repeat cesarean delivery in 2023 at a private clinic in Lebanon. Cases (n = 117) had intraoperatively diagnosed uterine scar dehiscence, whereas controls (n = 104) had intact scars. Maternal factors, inter-delivery interval, bleeding during pregnancy, anemia, urinary tract infection, gestational age, and LUS thickness, measured by ultrasound, were analyzed. Multivariable logistic regression identified independent predictors. RESULTS: LUS thickness <3 mm was strongly associated with uterine scar dehiscence (aOR, 13.49; 95% CI, 5.92-30.73; P = 0.001). Bleeding during pregnancy was also an independent predictor (aOR, 8.50; 95% CI, 3.47-20.85; P = 0.001), while a longer inter-delivery interval was protective (aOR, 0.80; 95% CI, 0.69-0.94; P = 0.006). Neonatal intensive care unit admission was higher among neonates born to mothers with dehiscence (16.2% vs. 5.8%; P = 0.014). CONCLUSION: Uterine scar dehiscence is associated with an LUS thickness <3 mm, bleeding during pregnancy, and shorter interdelivery intervals. Antenatal ultrasound assessment may improve risk stratification and outcomes in women with prior cesarean deliveries.