Role of clinical and ultrasound findings in the diagnosis of retained products of conception.

OBJECTIVE

To assess the role of clinical and ultrasound findings as predictors of retained products of conception (RPOC) in women with a suspicion of incomplete miscarriage.

METHODS

This was a retrospective study of 91 patients admitted for suspected RPOC after spontaneous first-trimester miscarriage who were evacuated surgically, and for whom histopathological reports were available. All the women underwent transvaginal sonography after their miscarriage. The decision to evacuate the uterus was based on vaginal bleeding, lower abdominal pain and/or sonographic findings of hyperechoic material or endometrial thickness more than 8 mm. Maternal age, gestational age, clinical signs and symptoms and sonographic findings were recorded. Clinical and sonographic findings were compared with the histopathological reports and the sensitivity and specificity of vaginal bleeding, abdominal pain and sonographic appearance of the endometrium for detecting the products of conception were assessed.

RESULTS

Histopathological analysis confirmed the presence of chorionic villi in 55 women (60%) and decidua in 36 (40%). Vaginal bleeding was more frequent in women with RPOC (P < 0.001), whilst lower abdominal pain was a more frequent symptom in those with decidua (P = 0.019). The ultrasound finding of hyperechoic material had a sensitivity of 78%, specificity of 100% and positive and negative predictive values of 100% and 75%, respectively, in predicting RPOC. Vaginal bleeding as a predictor of RPOC had a sensitivity of 93%, specificity of 50%, and positive and negative predictive values of 74% and 82%, respectively. The combination of hyperechoic material and/or vaginal bleeding increased the sensitivity to 98% and negative predictive value to 95%. There was no significant difference in endometrial thickness between the two groups.

CONCLUSION

The ultrasound finding of hyperechoic material is the best predictor for diagnosing RPOC. In the absence of hyperechoic material and vaginal bleeding, RPOC are extremely unlikely.