Bleeding patterns and safety of a low-dose levonorgestrel-releasing intrauterine system (13.5 mg) versus a copper intrauterine device: results of a 3-year, single- centre, randomized Phase IV study.

Abstract Objective. To compare the bleeding patterns associated with the 3-year use of copper intrauterine devices (Cu-IUD) or 13.5-mg levonorgestrel-releasing intrauterine systems (LNG-IUS) in clinical practice. Design. Single-centre, double-blind, randomized, parallel group, Phase IV study. Setting. Gynaecology office. Population or Sample. Women seeking long-term contraception, eligible to use Cu-IUD/LNG-IUS. Methods. At baseline and at months 3, 6, 12, 24 and 36 after placement, we recorded the number of bleeding days and quantity of bleeding: self-reported bleeding intensity, the Pictorial Blood Assessment Chart (PBAC) and haemoglobin/ferritin levels and haematocrit. The frequency and intensity of dysmenorrhoea and spotting, and of adverse events were also recorded. Main Outcome Measures. Bleeding days and quantity of bleeding in 90-day reference periods (RPs). Results. One-hundred six women aged 32.5±6.7 years participated in the study: 55 women were randomized to LNG-IUS and 51 to Cu-IUD. The median number of bleeding days and the bleeding intensity (self-perceived and PBAC score) were significantly lower with LNG-IUS throughout the study (P <0.001), with a greater reduction during RP2 (month 2 for PBAC). Ferritin levels increased with LNG-IUS and decreased with Cu-IUD. The frequency and intensity of dysmenorrhoea decreased significantly more with LNG-IUS vs Cu-IUD. The median number of spotting days was 0 or close to 0 throughout the study with both devices. Conclusions The 13.5-mg LNG-IUS shows benefits over the Cu-IUD in terms of menstrual bleeding pattern, being associated with significant blood loss reduction and greater reduction of the frequency and intensity of dysmenorrhoea, with similar patterns of spotting days.