Diagnostic Accuracy of Ultrasound in Placenta Accreta Spectrum Disorders

Abstract

Objective: To determine the diagnostic accuracy of ultrasound in detecting placenta accreta spectrum disorders by using operative and histopathological findings as the reference standard.

Material and Methods: This prospective diagnostic accuracy study was conducted at Mardan Medical Complex Mardan from 23 January 2022 to 23 September 2022. A total of 130 pregnant women with clinical risk factors or ultrasound suspicion of placenta accreta spectrum were enrolled through consecutive sampling. Targeted transabdominal ultrasound with color Doppler assessment was performed. Transvaginal ultrasound was added when required. Placental lacunae loss of the retroplacental clear zone myometrial thinning placental bulging bridging vessels and abnormal uterovesical vascularity were assessed. Ultrasound findings were compared with operative and histopathological diagnoses. Sensitivity specificity predictive values and overall accuracy were calculated.

Results: Placenta accreta spectrum was confirmed in 58 of 130 patients. Ultrasound correctly identified 54 affected patients and correctly excluded the disorder in 65 unaffected patients. Four false negative and seven false positive results were recorded. Sensitivity was 93.1 percent and specificity was 90.3 percent. Positive predictive value was 88.5 percent while negative predictive value was 94.2 percent. Overall diagnostic accuracy was 91.5 percent. Placental lacunae loss of the retroplacental clear zone myometrial thinning and increased subplacental vascularity were significantly associated with confirmed disease.

Conclusion: Ultrasound demonstrated high diagnostic accuracy for antenatal detection of placenta accreta spectrum disorders. Combined grayscale and color Doppler assessment was effective for identifying affected women and supporting planned obstetric management.

Keywords: Placenta Accreta, Ultrasonography, Prenatal Diagnosis, Placenta Previa, Pregnancy Complications, Diagnostic Imaging