Clinical and sonographic findings in suspected retained trophoblast: Correlation with histological findings

Background: Different clinical and sonographic parameters have been suggested to identify patients with retained products of conception. In suspected cases, the main treatment is hysteroscopic removal. Objectives: To compare clinical, sonographic, and intraoperative findings in cases of hysteroscopy for retained products of conception, according to histology. Methods: The results of operative hysteroscopies that were conducted between 2011 and 2016 for suspected retained products of conception were evaluated. Material was obtained and evaluated histologically. The positive histology group (n=178) included cases with confirmed trophoblastic material. The negative histology group (n=26) included cases with non-trophoblastic material. Results: Patient demographics were similar in the groups, and both underwent operative hysteroscopy an average of 7 to 8 weeks after delivery/abortion. A history of vaginal delivery was more common among the positive histology group. The main presenting symptom in all study patients was vaginal bleeding, and the majority of cases were diagnosed at their routine postpartum/abortion follow-up visit. Sonographic parameters were similar in the groups. Intraoperatively, the performing surgeon was significantly more likely to identify true trophoblastic tissue as such than to correctly identify non-trophoblastic tissue (P < 0.001). Conclusions: Suspected retained trophoblastic material cannot be accurately differentiated from non-trophoblastic material according to clinical, sonographic, and intraprocedural criteria. Thus, hysteroscopy seems warranted in suspected cases.