Effectiveness of office hysteroscopy for retained products of conception: insights from 468 cases

Retained products of conception (RPOC) are a common complication following pregnancy. Office hysteroscopy (OH) is increasingly used for diagnostics and management due to its minimally invasive nature. However, incidence of incomplete OH removal and procedures in which no RPOC are identified despite prior suspicion remains a concern. This study aimed to identify factors associated with these outcomes to improve patient selection and procedural success.

A retrospective study was conducted on patients referred for OH for presumed RPOC between August 2015 and April 2023 at the Department of Gynecology and Obstetrics, University Medical Centre Ljubljana, Slovenia. Inclusion criteria included hemodynamically stable patients with prolonged bleeding and/or suspicious ultrasound (US) findings post-pregnancy. Patients with RPOC thickness of more than 30 mm or strong tissue vascularization on US were excluded. Data on patient demographics, US features, and procedural outcomes were analyzed.

Out of the 468 patients, RPOC removal was performed in 333 cases (71.2%), of which 225 (67.6%) were successfully completed, while in 135 cases (28.8%), the procedure was only diagnostic due to the absence of RPOC. Regarding procedural success, neither the pregnancy outcome, i.e., termination of pregnancy (TOP) vs delivery, nor gestational age significantly correlated with it. Longer time from pregnancy end to OH significantly improved procedural success in both groups, after TOP (p = 0.025) and in cases of large RPOC after delivery (p < 0.001). Parity significantly altered procedural success only in the delivery group (p < 0.007). The success rate of the procedure was significantly higher in cases when only small RPOC were observed (p < 0.001). Absence of RPOC occurred more frequently following TOP than after delivery (p < 0.001). Procedures in which no RPOC were confirmed were significantly associated with a longer interval between pregnancy end and OH in both TOP (p = 0.013) and delivery group (p = 0.003). Gestational age significantly correlated with the absence of RPOC only in the delivery group (p = 0.003). The likelihood of not confirming RPOC was higher where US thickness and length were lower (p = 0.007 and p = 0.011, respectively).

OH is effective for managing RPOC with a high success rate, but the absence of RPOC in a considerable number of OH-treated patients stresses the need for better diagnostic criteria and patient selection to minimize overtreatments. Further prospective studies are needed to optimize the timing and indications for OH.