Purpose
To determine the best predictors of the presence of retained products of conception (RPOC) on grayscale and color Doppler transvaginal ultrasound examination
Materials & Methods
This was a retrospective study of 91 consecutive patients who underwent TVS with color Doppler to evaluate for the presence of RPOC. The images of TVS studies were reviewed by two radiologists in consensus blinded to the final outcome. Data on a number of variables including; endometrial mass, and focal increased color vascularity were collected as predictors of RPOC. The patients’ age ranged from 17 to 48 years (Mean 31.8±6.8) and gestational age from 5 to 24 weeks (Mean 9.2±3.8). Thirtysix
were confirmed as RPOC by D&C and pathology. Fifty-five were considered negative, 9 based on D&C results and 46 on clinical grounds.
Results
Sensitivity, specificity, negative and positive predictive and accuracy values were 81% (CI:68%-94%), 71% (CI:59%-83%), 85% (CI:74%-95%), 64% (CI:50%-78%), and 75% (CI:66%-84%) to detect RPOC when a mass was present. The corresponding numbers for the presence of focal color vascularity were 94% (CI:87%-100%) (p=0.07), 67% (CI:55%-80%) (p>0.05), 95% (CI:88%-100%) (p=0.1), 65% (CI:52%-78%) (p>0.05), and 78% (CI:70%-87%) (p>0.05). Six of patients with false positive diagnosis of RPOC based on the presence of a mass or focal vascularity had received Misoprostol after US. Of the patients with confirmed RPOC on pathology, 5 had focal increased vascularity and no mass and none had a mass without focal increased vascularity.
Conclusion
An area of focal increased vascularity ± a mass is the best predictor of the presence of RPOC.