RESUMO
To compare the contraceptive efficacy of various types of intrauterine devices (IUD; copper devices, Nova-T, intrauterine contraceptive systems, levonorgestrel-releasing devices), we reviewed all relevant publications on this subject that have been published over the last 2 decades. The first point to be highlighted by this review is the excellent effectiveness of IUDs, with a global cumulative pregnancy rate <2% at 5 years, whatever the type of device used. We observed a large variation in efficacy rate according to the type of IUD and also according to study design. Nevertheless, of all the types of IUDs, the levonorgestrel-releasing IUD and to a lesser extent the TCu380A IUD seem to be the most effective, with a cumulative pregnancy rate at 5 years of <0.5% for the levonorgestrel-releasing IUD and between 0.3% and 0.6% for the TCu380A IUD.