Ultrasound differentiation between benign versus malignant adnexal masses in pregnant patients

Objectives. The aim of this study was to assess the performance of the International Ovarian Tumor Analysis (IOTA) group ultrasound Simple Rules method in differentiating between benign and malignant ovarian tumors in pregnant patients. Materials and Methods. A prospective observational study that involved pregnant patients referred to our center due to suspicions of ovarian masses between January 2015 and December 2017 was performed. The Simple Rules performance was evaluated against the histopathological results. Each of the 10 sonographic Simple Rules were computed by logistic regression to demonstrate their odds ratios in predicting malignancy. Results. Ultrasound were conducted in 153 subjects, and 61 of those patients underwent surgery. By assigning masses not classifiable by Simple Rules as probably malignant, the Simple Rules method showed a sensitivity of 91.67% (CI 64.61–98.51) and a specificity of 69.39% (CI 55.47–80.48). After exclusion of masses where the Simple Rules method could not be applied, the method showed a sensitivity of 87.5% (CI 52.91–97.76) and a specificity of 94.44% (CI 81.86–98.46). The logistic regression model showed that the M-rules increased the risk of malignancy while the B-rules decreased the risk. Conclusion. Most ovarian masses in pregnant patient may be correctly categorized as benign or malignant using Simple Rules. This protocol may facilitate the management of pregnant patients presenting with adnexal masses.