Objective: Current research informations fail to adequately inform about when levonorgestrel-releasing intrauterine system (LNG-IUS) 52 mg is used instead of other lower dose LNG-IUSs (13.5 and 19.5 mg) and other long-acting reversible contraceptives (LARCs) in clinical practice.
Methods: A retrospective cohort study was performed in a third-level Service for Family Planning of Modena University hospital about all the first modern contraceptives prescriptions in the whole year 2019 performed by the same group of physicians. All women included underwent a detailed transvaginal ultrasound (TVUS) at prescription and a second evaluation within 3 months when they were still using the prescribed method.
Results: To 69/160 (43.1%) women a short-acting reversible contraceptive (SARC), while to 91/160 (56.9%) a LARC was prescribed. Women with a LARC prescription were older than them with a short-acting (SARC) (p < .0001). Women with LNG-IUS 52 mg prescription were significantly the oldest (42.9 ± 5.3), while those with intrauterine copper device and lower dose LNG-IUS were of similar age (36.5 ± 7.3 and 34.9 ± 2.3), significantly lower (p < .005). Women with implant prescription had the same age as SARC, being the youngest (30.7 ± 8.9 and 31.0 ± 9.5) (p < .0001). Women with LNG-IUS 52 mg prescription mg presented with bigger uterine volume (p = .001). In multivariate analyses, the LNG-IUS 52 mg prescription was significantly linked only to age (OR 1.24; 95% CI 1.11-1.37, p < .0001) and presence of adenomyosis (OR 4.56; 95% CI 1.45-14.33, p = .009).
Conclusions: The use of LNG-IUS 52 mg instead of other LARCs is preferred for older women, with uteri of increased volume due to adenomyosis, suggesting a possible differential use of available LNG-IUSs in the contemporary clinical practice.
Keywords: Benilexa; Jaydess; Kyleena; LARC; Levonorgestrel-releasing intrauterine system; Levosert; Mirena; SARC; Skyla; contraception; implant; intrauterine.