Assessment of the Transfer of Using Levonorgestrel Intrauterine System (LNG IUS) as a Contraceptive to Using it as Part of Hormone Replacement Therapy (HRT).

LNG IUS (initial in vitro release 20 µg/24h) intrauterine for minimum of 9 months and maximum of 60 months - 2 phases: a) Contraception Phase b) HRT Phase. For outcome measures (vaginal bleeding variables), five 90-day Reference Periods were defined, which were used for comparison during statistical analysis: Reference Period -1 in Contraception Phase; Reference Periods 1-4 in HRT Phase. 90-day reference periods for analyzing vaginal bleeding data are defined by WHO guideline. Reference Period -1 is the last 90-day reference period that the subject had before starting the HRT. Reference Period 1 covers the first 90-days of the HRT phase, Reference Period 2 covers days 91 to 180, Reference Period 3 days 181 to 270, and Reference Period 4 days 271 to 360 of the HRT phase.