Evaluation of the accuracy of transvaginal sonography for the assessment of retained products of conception after spontaneous abortion.

Transvaginal sonography (TVS) was used to assess uterine contents in 100 consecutive subjects presenting with a diagnosis of spontaneous abortion. TVS assessments were correlated with findings at subsequent evacuation of retained products of conception (ERPC). There was a strong correlation between the weight of the surgical specimen at ERPC with both the sagittal (r = 0.76; p < 0.05) and transverse (r = 0.73; p < 0.05) plane area measurements of the uterine cavity. Combining the 2 sonographic measurements increased the correlation to r = 0.81 (p < 0.05). Fifteen of 25 subjects who had been categorised to have an 'empty' uterus had less than 5 g of tissue removed and the other 10 subjects less than 10 g of tissue. In 20 of these 25 cases, the surgeon described the amount of curettings as 'small or non-significant'. TVS can accurately identify those women who do not have a significant amount of residual uterine tissue following spontaneous abortion.