The primary objective of the study is to assess the contraceptive failure risk of Jaydess, Mirena, and copper IUD use in a study population that is representative of the real users of the individual IUDs. Interim analysis showed a high proportion of IUD users in the age group >= 40 years of age. Given the fact that the age distribution remains considerably skewed, and that the Pearl Index is influenced by the age of participants, the independent Safety Monitoring and Advisory Council decided to suggest to narrow the study inclusion criteria, i.e. an age restriction to <40 years old at study entry was suggested for the remaining recruitment phase.