Predictors of oligoamenorrhea at 1-year follow-up in premenopausal women using a levonorgestrel-releasing intrauterine system.

OBJECTIVE The study was conducted to identify predictors of oligoamenorrhea at 12 months in levonorgestrel-releasing intrauterine system (LNG-IUS) users. DESIGN A 12-month observational study. SETTING Gynecologic outpatient clinic in a large regional hospital in Flanders, Belgium. POPULATION OR SAMPLE A total of 150 women who had made an informed decision to use a LNG-IUS either as a method of contraception or to manage menorrhagia. METHODS All women were premenopausal and first-time users. The variables recorded prior to insertion on Days 1 to 5 of the menstrual cycle were age, parity, body mass index, indication for LNG-IUS use, prior contraceptive use, menstrual bleeding history, length of the uterine cavity, endometrial thickness, number of antral follicles, serum follicle-stimulating hormone, inhibin B and anti-Müllerian hormone. Menstrual bleeding pattern, patient satisfaction or wish to discontinue the method was noted at 3, 6 and 12 months of follow-up visits. MAIN OUTCOME MEASURES Menstrual bleeding pattern (amenorrhea, oligomenorrhea, menorrhagia) at 12 months was taken as the primary outcome measurement. Patient satisfaction was followed as a secondary outcome. RESULTS Oligoamenorrhea was associated with a high patient satisfaction. A bleeding period less than 5 days, absence of severe uterine bleeding at baseline, LNG-IUS use for contraception and oligoamenorrhea at 3 months were predictors of a favorable outcome at 12 months in a univariate analysis. The absence of severe bleeding prior to LNG-IUS insertion was the only clinically useful predictor of favorable outcome in the multivariate analysis (odds ratio 0.13, 95% confidence interval 0.02-0.66). CONCLUSIONS Patient profiling as described is not helpful in counselling women for intentional LNG-IUS use, especially not if it is planned as a method of managing menorrhagia.