RESUMO
Objective To evaluate the efficacy,bleeding profile and safety of low-dose levonorgestrel-releasing intrauterine system (LNG-IUS 8) in Chinese healthy women of childbearing age.Methods A multi-center,open-label,single-arm clinical trial conducted at 16 centres in China enrolled 773 healthy women of childbearing age (mean age 31.6 years old,range 18 to 40 years old),who demanded contraception,from April 2006 to June 2013.All women placed LNG-IUS 8 for 3 years and then been followed up at 3,6,9,12,18,24,30,36 months.The efficacy variables including pregnancy rate and expulsion rate were analyzed using life table,while observing adverse events (AE) to evaluate the safety.The bleeding profile happened during the study was assessed using 90-day reference intervals (World Health Organization criteria).Results Eight pregnancies occurred among 773 women,resulting in a overall Pearl index of 0.42 per 100 women years.The 3-year cumulative pregnancy rate was 0.37 per 100 women years and the 3-year cumulative expulsion rate was 1.99 per 100 women years.The number of women with bleeding/spotting reduced and the bleeding/spotting days declined over time.Totally 219 AE were reported related to LNG-IUS 8 placements.The most common AE were vaginal bleeding (8.2％,63/773)and the ovarian cyst (6.2％,52/773).LNG-IUS 8 had an improving effect on dysmenorrhea that the percentage of women with dysmenorrhea as well as the days of dysmenorrhea decreased over time.The percentage of women satisfied or very satisfied with LNG-IUS 8 was 87.2％ (622/713).Conclusion LNG-IUS 8 is highly effective and safe for Chinese healthy women of childbearing age.