Can Ultrasound Predict the Presence of Retained Products of Conception Following First-Trimester Spontaneous Abortion?

Background: The incidence of retained products of conception (RPOC) has been reported as 1-3% and ultrasound has an important role in their diagnosis and selection of patients for surgical management. The aim of this study is to identify that ultrasound is a predictor of the presence of retained product of conception (RPOC) within the uterine cavity in women with the clinical diagnosis of incomplete first trimester abortion. Methods: One hundred patients with a diagnosis of incomplete abortion and RPOC based on clinical and sonographic findings were enrolled. The gold standard test was pathologic reports of samples obtained during dilatation and curettage. Endometrial thickness and homogenesity of the endometer were determined by sonography. The sensitivity and specificity of the measurements for detecting RPOC were assessed. Results: Histopathological reports confirmed the diagnosis of RPOC in 71 patients (71%). Mean endometrial thickness with RPOC was 16.3 mm versus 12.1 mm without RPOC. Heterogenic endometrium was seen in 56 out of 71 patients (78 %). The sensitivity and specificity of the endometrial thickness greater than 11.25mm for detecting RPOC were 81% and 45%, respectively. Regarding the endometrial thickness and heterogenic endometer, 13.5 mm had the best performance criteria with 60% and 63% sensitivity and specificity, respectively. Conclusion: An endometrial thickness of 11.25 mm or more detected by sonography had the best diagnostic efficacy, considering the heterogenecity with the thickness of the endometrium, 13.5 mm had the best performance criteria for detection of RPOC following first trimester spontaneous abortion.