Objective: To describe clinical and paraclinical characteristics and assess the prognostic value of the Shih and COS classifications in cesarean scar pregnancy under 10 weeks’ gestation.
Methods: Cross-sectional study of 280 medical records from Hanoi Obstetrics and Gynecology Hospital (January-December 2024). Collected variables included clinical features, ultrasound findings, β-hCG, and management method; prognostic value was evaluated using ROC curves.
Results: Mean maternal age was 35.4 ± 5.1 years; mean gestational age 6.7 ± 1.2 weeks. Two prior cesarean sections accounted for 54.6%; an interval since the most recent cesarean ≥ 4 years occurred in 43.9%. Vaginal bleeding was common (43.9%); 16% were asymptomatic. Fetal cardiac activity increased with gestational age (100% at week 10). Marked hypervascularity was present in 49.6% and rose with gestational age. The gestational sac was most often oriented toward the uterine cavity (58.2%). β-hCG > 10,000 IU/L occurred in 78.9%. Suction evacuation was the predominant treatment (69.3%); overall success rate was 95%, with low complication rates (minor bleeding 1.1%; hemorrhage 2.5%; hematoma 3.6%). The Shih classification showed an AUROC of 0.64 (limited value); the COS classification had an AUROC of 0.54 (near non-discriminatory).
Conclusions: Early ultrasound screening-integrating sac morphology, hypervascularity, and β-hCG-supports individualized management of cesarean scar pregnancy. Ultrasound-guided suction evacuation is a safe, effective option when diagnosed early; standalone morphologic classification systems provide limited prognostic value.