Multi-Center, Open-Label, Randomized Study to Assess the Safety and Contraceptive Efficacy of Two Doses ( in vitro12 µg/24h and 16 µg/24h) of the Ultra Low Dose Levonorgestrel Contraceptive Intrauterine Systems (LCS) for a Maximum of 3 Years in Women 18 to 35 Years of Age and an Extension Phase of the 16µg/24h Dose Group (LCS16 Arm) up to 5 Years

This is a study on a new low dose levonorgestrel contraceptive intrauterine systems (LCS). The purpose of the study is to investigate which of the 2 administered doses is the lowest effective intrauterine dose of Levonorgestrel (LNG) administered via the LCS for contraception during 3 years. The study was amended: the LCS16 arm will be extended up to 5 years