Microdose intrauterine levonorgestrel for contraception. World Health Organization Special Programme of Research, Development and Research Training in Human Reproduction: Task Force on Intrauterine Devices for Fertility Regulation.

An intrauterine device (IUD) releasing 2 micrograms of levonorgestrel per 24 hours was compared in a randomized multicentre clinical trial with two copper IUDs-the TCu 220C and the Nova T. The 2 micrograms levonorgestrel device had statistically significantly higher pregnancy rates (from 390 days of use) and higher expulsion rates (up to 570 days). In addition, the total medical removals and removals for bleeding were significantly higher at all intervals where the data were analysed. Most disturbing was a 6.7 increased relative risk of ectopic pregnancy with the steroid-releasing IUD compared to the combined copper IUD data. It is concluded that the goal of microdose administration of 2 micrograms levonorgestrel to the uterine cavity does not achieve the objectives of a new and improved IUD device which is safe and effective.