Study question: What is the bleeding pattern during second consecutive levonorgestrel-releasing intrauterine system (LNG-IUS) use?
Summary answer: Consecutive use of LNG-IUS is associated with a predictable bleeding pattern, characterized by the absence of the initial period of irregular bleeding seen after interval insertion of an LNG-IUS and a non-bleeding pattern in the vast majority of women.
What is known already: With increased popularity of the LNG-IUS for long-term birth control and treatment of heavy menstrual bleeding (HMB), consecutive use of the system is becoming more frequent. One previous study showed 60% amenorrhea rate in consecutive IUS users; however, the sample size was small.
Study design, size, duration: A prospective multicenter study in four European countries recruited women who wished to continue with LNG-IUS use immediately after the first 5-year period. A total of 204 women were followed up until the end of the first year of the second IUS. Thereafter 170 women continued into the extension phase of the study up to the full 5 years of use of the second IUS and 144 women continued to the end of the study.
Participants, setting, methods: A total of 170 women (mean age 39 years) who had been using their first LNG-IUS for between 4 years 3 months and 4 years 9 months, either for contraception or for treatment of HMB, and who planned to replace the device with a new LNG-IUS, were recruited and followed up to 5 years of the second IUS use. A total of 17 centers in four European countries were involved in the study. Bleeding patterns were analyzed using daily bleeding diaries using 90-day reference periods (RP) for the first year of the second IUS use and for the last RP of each year during Years 2-5 of use.
Main results and the role of chance: Approximately 70% of women were free of bleeding during Years 2-5 and up to 49% were amenorrheic. There was a slight increase in the number of bleeding/spotting days of ∼3 days during the first RP immediately after the placement of the second IUS, whereafter the number of bleeding/spotting days returned to the level preceding the second IUS insertion or below that. Absence of bleeding was associated with high overall satisfaction and continuation rates. No serious adverse events assessed as related to the LNG-IUS use occurred during the 5-year period. The cumulative expulsion rate during the 5-year study period was 1.2%. The sample size was large enough to study bleeding patterns, and subjects are likely to represent typical consecutive IUS users, and therefore, the role of chance is small.
Limitations, reasons for caution: The women represent a selected group as they had already successfully used their first IUS for almost 5 years and were willing to continue its use-however, this is currently a common clinical situation. The results may therefore not be extrapolated to first-time users of the LNG-IUS.
Wider implications of the findings: These data are of importance when counseling women who are making decisions concerning long-term contraception.
Study funding/competing interest(s): This study was funded by Bayer Pharma AG. P.I. and T.S. are full-time employees of Bayer Pharma AG. O.H. and K. G-D. have received consultancy fees from Bayer Pharma AG. The publication was developed jointly by all authors without third-party involvement and no honoraria were paid for any authors for their contribution to this manuscript.
Trial registration number: NCT00393198.
Keywords: bleeding; intrauterine device; intrauterine system; levonorgestrel; long-term.