COMPARISON BETWEEN TRANSABDOMINAL AND TRANSVAGINAL SONOGRAPHY IN DETECTION OF RETAINED PRODUCTS OF CONCEPTION

Background: Retained products of conception (RPOC) refer to placental or fetal tissue remaining in the uterus after delivery or miscarriage, potentially leading to complications such as abnormal bleeding, infection, and infertility. The incidence of RPOC varies, occurring in 17% of cases after the first trimester, 40% after the second trimester, and 3–5% following normal delivery. Accurate and timely diagnosis is crucial, with ultrasonography serving as a primary diagnostic tool. Objective: To determine the diagnostic accuracy of transabdominal sonography (TAS) and transvaginal sonography (TVS) in detecting retained products of conception, using histopathology as the gold standard. Methods: This cross-sectional validation study was conducted from May 1, 2022, to November 1, 2022, at the Department of Diagnostic Radiology, PAF Hospital, Islamabad. A total of 345 women aged 18–40 years with clinical suspicion of RPOC were included. TVS was performed using an endocavity transducer, with RPOC defined as echogenic or heterogeneous material in the endometrial cavity with a thickness >10 mm. TAS was conducted using a convex probe with a diagnostic criterion of an irregular mass measuring ≥10 mm within the endometrial cavity. All findings were compared against histopathological results as the reference standard. Statistical analysis was performed using SPSS. Results: The mean age of participants was 29.61 ± 2.40 years, with a mean gestational age of 15.96 ± 1.68 weeks, mean parity of 1.93 ± 1.34, and mean abortion duration of 17.09 ± 5.77 days. TVS exhibited a sensitivity of 89%, specificity of 74.5%, diagnostic accuracy of 87%, positive predictive value (PPV) of 95.2%, and negative predictive value (NPV) of 54.3%. TAS demonstrated a sensitivity of 88.4%, specificity of 54.9%, diagnostic accuracy of 83%, PPV of 91.87%, and NPV of 45%. Conclusion: Transvaginal sonography demonstrated superior diagnostic accuracy, sensitivity, and specificity compared to transabdominal sonography, confirming its utility as the preferred imaging modality for diagnosing retained products of conception.