Diagnostic Accuracy of Colour Doppler Ultrasound in Antenatal Diagnosis of Morbidly Adherent Placenta, Taking Operative Finding as Gold Standard

CDU in Morbidly Adherent Placenta and Taking Operative Finding as Gold Standard

Abstract

Morbidly adherent placenta (MAP), often linked to prior cesarean delivery, is a serious obstetric condition requiring timely Doppler ultrasound diagnosis despite variable specificity. Objectives: To evaluate the diagnostic accuracy of Color Doppler ultrasound (CDUS) for antenatal detection of MAP, using intraoperative findings as the reference standard. Methods: This was a comparative analytical study with a retrospective review of patient data conducted in the Department of Diagnostic Radiology at Aga Khan University spanning April to August 2025 and included pregnant women via consecutive sampling identified as being at risk for MAP. Each participant underwent an antenatal ultrasound assessment, and the sonographic findings were subsequently compared with operative findings. Diagnostic indices such as sensitivity, specificity, positive and negative predictive values, as well as overall accuracy, were determined. Results: Color Doppler ultrasound exhibited strong diagnostic performance in detecting MAP, achieving a sensitivity of 98.10 % (95% CI: 93.29-99.77) and a specificity of 55.56 % (95% CI: 35.33-74.52). The point receiver operating characteristic (ROC) curve demonstrated an area under the curve (AUC) of 0.89, indicative of excellent discriminatory capacity. Diagnostic accuracies were observed as 90.48% for accreta (p<0.001), 89.19% for increta (p<0.001), and 79.17% for percreta (p<0.001). Subgroup analysis showed the same accuracy in women aged ≤35 years (98.08%) and those >35 years (98.08%). Conclusions: Doppler ultrasound showed high diagnostic accuracy for MAP with excellent ROC performance and consistent sensitivity across maternal age and gestational subgroups.