Expulsion of a Levonorgestrel-releasing Intrauterine System: a Retrospective Analysis

Abstract

Objective: To report the incidence of expulsion of a levonorgestrel-releasing intrauterine system (LNG-IUS) in Chinese patients and to determine the associated risk factors.
Methods: Medical records of patients who underwent insertion of a LNG-IUS between 1 November 2008 and 31 January 2017 at Tuen Mun Hospital were reviewed. The primary outcome was complete or partial expulsion of the device. Patients with or without expulsion were compared to determine the associated risk factors.
Results: A total of 185 patients (mean age, 44 years) with 263 episodes of LNG-IUS insertion were analysed. The mean follow-up was 38.49 (range, 3-113) months; 84.8% of patients were parous. The most common indication for insertion was menorrhagia (73.4%), followed by endometrial hyperplasia without atypia (24%), and endometrial hyperplasia with atypia (3%). The expulsion rate was 35% (n=92); 76 were complete and 16 were partial. 84.8% of expulsions occurred within the first year of insertion; the median time to expulsion was 4 (range, 1-53) months. Compared with patients without expulsion, those with expulsion were more likely to be parous (91.3% vs. 81.3%, p=0.031), have an abdominally palpable uterus (10.9% vs. 4.1%, p=0.033), a longer uterine cavity (8.51 vs. 8.04 cm, p=0.001), fibroids (44.6% vs. 29.8%, p=0.017), adenomyosis (23.9% vs. 11.1%, p=0.006), and the indication for insertion being menorrhagia (94.6% vs. 62%, p<0.001) or dysmenorrhoea (29.3% vs. 12.9%, p=0.001). In multivariable analysis, risk factors for expulsion were an abdominally palpable uterus (adjusted hazard ratio=2.01, p=0.04), menorrhagia (adjusted hazard ratio=6.59, p<0.001), and dysmenorrhoea (adjusted hazard ratio=1.96, p=0.005). 27 patients underwent reinsertion of a LNG-IUS after expulsion; 13 (48.1%) of whom experienced reexpulsion.
Conclusion: Patients with menorrhagia and dysmenorrhoea are at higher risk of expulsion of LNG-IUS. To reduce the risk of expulsion, the LNG-IUS should be inserted during the later part of the menstrual cycle after pregnancy has been excluded. For patients with an abdominally palpable uterus, the LNG-IUS may not be suitable as the firstline management for menorrhagia or dysmenorrhoea owing to the high risk of expulsion; detailed counselling and frequent follow-up should be provided.