Diagnostic Accuracy of Endometrial Thickness in Identifying Retained Products of Conception and Tailored Hysteroscopic Management: A Retrospective Study

Objectives: Retained products of conception (RPOC) can occur after delivery, abortion, or uterine evacuation, presenting diagnostic challenges. This study aimed to assess the diagnostic accuracy of transvaginal ultrasound (TVS) endometrial thickness measurements for identifying RPOC and propose tailored hysteroscopic management strategies. Design: This is a retrospective cohort study. Participants and Setting: A total of 226 women with suspected RPOC underwent hysteroscopy between 2018 and 2021 at the Galilee Medical Center. Methods: Endometrial thickness was measured by TVS, and diagnostic metrics, including sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were calculated. Results: The mean endometrial thickness was 1.6 cm (0.7-6 cm). The overall PPV for RPOC was 79.2%, with a false-positive rate of 20.7%. A cut-off of 1.49 cm yielded a sensitivity of 69.8%, specificity of 59.6%, PPV of 86.8%, and NPV of 34.1%. Women with thickness >1.49 cm had a threefold increased likelihood of RPOC. Stratifying by endometrial thickness showed PPVs of 54.5%(<10 mm), 76.5% (10-20mm), and 98.0% (>20mm). Limitations: Retrospective design may introduce selection bias, and findings require validation in larger, prospective studies. Conclusions: An endometrial thickness above 1.49 cm significantly increases the likelihood of RPOC confirmation. RPOC can occur in asymptomatic women with associated risk factors. TVS endometrial thickness measurements are effective for diagnosing and managing these cases, and stratification further enhances diagnostic accuracy.