Role of three-dimensional pelvic ultrasound in the assessment of risk factors for intrauterine device misplacement and dislocation

Abstract

Objectives: Our objectives were to improve the quality and safety of future intrauterine device (IUD) insertion by introducing a systematic approach to identifying patients at risk for IUD misplacement and dislocation using the 3D ultrasound. Design: Risk factors for IUD misplacement and dislocation were assessed in a case-control study of patients who presented to our ultrasound clinic for IUD localization: 49 cases (women with IUD misplacement and/or dislocation) were compared to 108 controls (women with IUDs in the normal position). Adjusted odds ratios (AOR), 95% confidence intervals (CI), and pvalues were calculated from logistic regression models using Firth’s penalized maximum likelihood estimation to reduce bias. Results: The most common type of IUD complication was caudal dislocation in the lower uterine segment (LUS) and/or cervix, with or without an embedment, occurring in 41 patients (83.67%). The presence of submucosal and/or intracavitary uterine fibroids (vs other fibroid location or no fibroids) was positively associated with IUD misplacement and dislocation: AOR = 19.24, 95% CI: 1.42–260.23, p = 0.03. The presence of sonographic features of adenomyosis was positively associated with IUD dislocation, AOR = 7.40, 95% CI: 2.71–20.24, p < 0.0001. Both narrow (<30 mm) and wide (>32 mm) uterine cavity transverse diameters of the fundus assessed in the coronal plane increased the odds of a displaced IUD (vs a diameter of 30–32 mm): narrow diameter AOR = 4.95 (95% CI: 1.41–17.36, p = 0.013), and wide diameter AOR = 5.44 (95% CI: 1.39–21.22, p = 0.015). The AOR for IUD dislocation for a uterine cavity length of <30 mm (vs 30 mm or greater) was 3.60, 95% CI: 1.40–9.21, p = 0.008. Copper-containing IUDs (TCu380A/ParaGard®) were displaced more frequently than other types of IUDs: AOR = 2.82, 95% CI: 1.04–7.65, p = 0.04. Conclusion: Our data confirm that 3D ultrasound is the method of choice for IUD localization and can be used for the objective selection of candidates for intrauterine contraception.