Dimensions of the Endometrial Cavity and the Outcome of Inserted Copper T380A Intrauterine Devices

Background: The intrauterine device (IUD) is an important long acting reversible contraceptive (LARC). Reduced contraceptive effectiveness and unintended pregnancy result from IUD displacement or expulsion. One theory about IUD displacement or expulsion is because the size of the uterus cavity and the IUD are incompatible. Objective: This study aimed to evaluate the association between endometrial cavity diameters and IUD displacement or expulsion. Methods: This cohort study was conducted at the Department of Obstetric & Gynecology of Menoufia University Hospital and Qwesna Central Hospital. The study included all women who were seeking contraception by intrauterine device (copper T380A IUD) during the period from March 2022 till December 2023. Ultrasound evaluation of endometrial cavity dimensions (axial length, transverse and antero-posterior diameters) and IUD position was performed for all participants immediately after insertion and during the follow-up visits (1 week. 1 month and 3 months post-insertion). All studied women were divided into 2 groups: Cases and control groups. The control group involved women who had maintained intrauterine IUD without expulsion or displacement. Cases are participants who had IUD expulsion or displacement during insertion or during the follow-up visits. The primary outcome of the study was the association between the endometrial cavity diameters and IUDs displacement or expulsion. Results: There was no significant difference between the studied groups regarding demographic or clinical patient characteristics. Longest transverse diameter (LTD), length of uterine cavity (LUC) and ant-post diameter (APD) were significantly increased among cases (53.14 ± 6.33, 44.86 ± 8.89 and 44.50 ± 5.90 respectively) than controls (36.82 ± 1.92, 37.78 ± 5.06 and 38.61 ± 7.75 respectively, P<0.05). Rates of displacement of IUD among cases at admission, during 1st week and 1st month were 30.8%, 35.9% and 10.3% respectively. Regarding expulsion rate of IUD, no cases with IUD expulsion was reported at admission, 1week and 1 month post-insertion, while only 4 cases suffered from IUD expulsion at 3 months post-insertion. Conclusion: Increased endometrial cavity dimensions was associated with displacement of the IUD.