DIAGNOSTIC ACCURACY OF ULTRASONOGRAPHY IN DETECTION OF MORBIDLY ADHERENT PLACENTA TAKING SURGICAL FINDINGS AS GOLD STANDARD

Abstract

Objectives

To evaluate the diagnostic accuracy of ultrasonography in the antenatal detection of morbidly adherent placenta in high-risk pregnancies, using intraoperative surgical findings as the gold standard.

Methodology

A prospective cross-sectional diagnostic accuracy study was conducted at a tertiary care hospital in collaboration between the Departments of Obstetrics and Gynecology and Radiology. A total of 120 pregnant women with clinical suspicion of morbidly adherent placenta, based on risk factors such as placenta previa, previous cesarean sections, or uterine surgery, were enrolled through non-probability consecutive sampling. All participants underwent detailed third-trimester ultrasonography using grayscale and color Doppler by experienced radiologists blinded to surgical findings. Sonographic markers assessed included placental lacunae, loss of the retroplacental hypoechoic zone, myometrial thinning, increased uteroplacental vascularity, and bridging vessels. Intraoperative findings during cesarean delivery served as the reference standard. Diagnostic parameters including sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy were calculated.

Results

The mean maternal age was 32.6 ± 4.8 years, and the mean gestational age at delivery was 36.9 ± 1.4 weeks. Ultrasonography suggested morbidly adherent placenta in 78 (65.0%) cases, while surgical confirmation was obtained in 72 (60.0%) cases. Placenta accreta was the most common subtype. Ultrasonography demonstrated a sensitivity of 91.7%, specificity of 77.8%, positive predictive value of 84.6%, negative predictive value of 87.5%, and overall diagnostic accuracy of 90.0% (p < 0.05). Confirmed cases were associated with increased blood loss, higher transfusion requirements, and longer operative times.

Conclusion

Ultrasonography is a highly sensitive and reliable modality for the antenatal diagnosis of morbidly adherent placenta and plays a crucial role in preoperative planning and reduction of maternal morbidity in high-risk pregnancies