A simplified ultrasound-based scoring system for predicting placenta accreta spectrum disorders in Korean women: a prospective study

Objective: Placenta accreta spectrum disorders (PASD) are life-threatening condition requiring early identification. This study aimed to identify maternal and sonographic predictors of PASD in a Korean population and to evaluate the diagnostic performance of a simplified ultrasound-based scoring system. Methods: In this prospective study of 238 pregnant women undergoing ultrasound screening, we compared the prevalence of established PASD features between those with and without confirmed PASD. To enhance clinical applicability, each ultrasonographic feature was assigned a weight of one point, and the cumulative score was assessed for its predictive performance. Results: Nineteen women (7.9%) were diagnosed with PASD. Prior uterine surgery was significantly more frequent in the PASD group (42.1% vs. 19.6%, p = 0.027), whereas the rate of previous cesarean section was not significantly different. The key ultrasound predictors were loss of clear zone, myometrial thinning, abnormal placental lacunae, placental lacunae feeder vessels, and uterovesical hypervascularity. A cutoff score of ≥2 points yielded a sensitivity of 63.2%, specificity of 77.2%, positive likelihood ratio (LR+) of 2.77, and negative likelihood ratio (LR−) of 0.48. Conclusion: In a low-birth-rate country such as Korea, the contribution of previous cesarean delivery to PASD risk may be less pronounced than in other populations. Most ultrasound features were reliably assessed, and the presence of two or more features demonstrated moderate predictive accuracy for PASD. This simplified ultrasound-based scoring system can therefore serve as a practical and clinically useful tool for prenatal risk stratification of PASD.