Accurate Detection of Retained Products of Conception after First- and Second-trimester Abortion by Color Doppler Sonography

ObjectiveThe aim of this study was to identify the role of transvaginal color Doppler and gray-scale ultrasonography findings in managing first- and second-trimester miscarriges.MethodsA prospective interventional study was conducted from March 2009 to April 2010 in our center in which 77 women with first- and second-trimester abortion were recruited. All women were evaluated by transvaginal grayscale and color Doppler ultrasonography. Blood flow within the endometrium was measured using color Doppler. Pulsed Doppler was performed to evaluate blood flow impedance by calculating the resistance index (RI).ResultsForty-six patients underwent dilation and curettage of which 67.4% were proven to have retained products of conception (RPOC). Thirty-one patients were followed up through expectant management. Endometrial thickness (ET) was greater in the group with RPOC (p < 0.001). The sensitivity, specificity, and positive and negative predictive values with 95% confidence intervals of vascularity for detecting RPOC were 88% (72–97%), 68% (52–81%), 67% (51–81%), and 88% (73–97%), respectively. RI was significantly lower (p = 0.004) among these patients. Echogenic mass was detected in 93.9% of women with RPOC, but only in 22.7% of the cases without retained tissues (p < 0.001). Transvaginal grayscale ultrasonography was 100% sensitive in detecting RPOC when ET was >10 mm. The combination of vascular pattern and endometrial echogenic mass was the most sensitive and specific ultrasonographic feature for detecting RPOC (88%; 95% confidence intervals: 79–95).ConclusionTransvaginal color Doppler ultrasonography can be used to verify the presence of RPOC after spontaneous miscarriges.