The value of measuring endometrial thickness and volume on transvaginal ultrasound scan for the diagnosis of incomplete miscarriage.

Abstract

To identify ultrasound measurements that are the best predictors of the presence of retained products of conception (RPOC) within the uterine cavity in women with clinical diagnosis of incomplete miscarriage. This was a prospective observational study, set in a dedicated early pregnancy assessment unit in a London teaching hospital. Endometrial thickness and the volume of suspected retained products of conception were measured by transvaginal ultrasound scan preoperatively. Indications for surgical intervention were heavy vaginal bleeding or continuous bleeding lasting > 7 days. The main outcome measure was histological evidence of chorionic villi in surgical specimens. Among the patients, 109 (85%) had evidence of chorionic villi on histology, whilst decidua was only found in the remaining 19 (15%). There was no identifiable cut-off for endometrial thickness or volume that could be used to differentiate between retained products of conception and decidua. Measurements of endometrial thickness or volume on ultrasound scan are not good tests for diagnosing an incomplete miscarriage.