Diagnostic Accuracy of Ultrasound in Detecting Retained Products of Conception: A Study from a Tertiary Care Hospital in Karachi, Pakistan

Introduction Retained products of conception (RPOC) are a known complication after abortion or childbirth. To improve clinical evaluation and avoid unnecessary surgery, transvaginal scan is performed in suspected cases. However, both RPOC and blood clots appear isoechoic on ultrasound, and false positives can lead to unnecessary intervention. In this study, the ultrasound findings have been correlated with the histopathology (as a gold standard) to determine the diagnostic value of sonography in the detection of RPOC in postpartum or post-abortion patients. Methods This cross-sectional study was carried out to determine the diagnostic accuracy of ultrasound in the detection of the retained products of conception in relation with the histopathological findings at the Department of Radiology, Aga Khan University Hospital (AKUH), Karachi. A total of 193 patients with suspicion of RPOC undergoing a transvaginal scan in the Department of Radiology, AKUH, were enrolled. The study was conducted for a period of 12 months from October 2014 to October 201S. Results Our results yielded that out of 193 cases, 113 cases (87.05%) had histopathology positive for RPOC, while 107 (55.44%) RPOC cases were identified by ultrasound as having RPOC. The mean endometrial thickness of the patients included in the study was 13.5 mm. According to our results, ultrasound has a sensitivity of 75.22%, specificity of 72.50%, a positive predictive value (PPV) of 79.44%, a negative predictive value (NPV) of 67.44%, and a diagnostic accuracy of 74.09%. Conclusion Transvaginal ultrasound is a modality that can be used for early diagnosis of the retained products of conception including fetal parts and could prove to be lifesaving. However, the operator and equipment variables need to be looked at, and a uniform criterion needs to be agreed on.