The Effect of Intrauterine Device Use on the Quality of Sampling Material in Patients Undergoing Endometrial Biopsy

Objective: This retrospective study aims to evaluate the effect of copper intrauterine device (Cu-IUD) use on the adequacy and diagnostic quality of endometrial biopsy specimens in women with abnormal uterine bleeding (AUB). Patients with levonorgestrel-releasing intrauterine systems (LNG-IUS, e.g., Mirena) were excluded from the study. The study compares the histopathological adequacy of endometrial samples between Cu-IUD users and non-users, highlighting potential interpretation challenges in routine pathological assessment. Methods: The study was conducted on 409 women aged 25–55 who presented with abnormal uterine bleeding (AUB) to the Gynecology and Obstetrics Outpatient Clinic at Kayseri City Hospital between 1 April 2021 and 1 April 2023. The patients were divided into two groups: copper IUD (Cu-IUD) users (n = 215) and non-IUD users (n = 194). Patients using levonorgestrel-releasing intrauterine systems (LNG-IUS, e.g., Mirena) were excluded from the study. Endometrial biopsies were obtained using the Pipelle curette technique without anesthesia, preserved in 10% formalin, and assessed for pathological classification and diagnostic adequacy. Results: The proportion of unclassifiable pathological categories was significantly higher in copper IUD users (63.93%) compared to non-IUD users (36.05%) (p = 0.013). Additionally, a negative correlation was observed between pathological category and endometrial thickness (r = −0.3147, p < 0.001), suggesting that thinner endometrial lining may reflect atrophic or diagnostically ambiguous tissue patterns. However, no significant association was found between IUD use and endometrial thickness (p = 0.073). Conclusions: The findings indicate that copper IUD use may affect the diagnostic adequacy of endometrial biopsy specimens, likely due to inflammatory or structural changes in the endometrium. These results underline the importance of considering IUD-related alterations when interpreting biopsy findings. Further research is needed to refine diagnostic approaches and better understand the clinical implications of these effects.