One of the most effective methods
The Levonorgestrel Intrauterine System (LNG IUS) is one of the most effective and long-acting contraceptive methods available. During the first year of LNG IUS use, the pregnancy rate is 1 to 3 per 1,000 women — a pregnancy rate of less than 1%. After the first year, there is a low risk of pregnancy throughout the duration of LNG IUS use — 5 to 8 pregnancies per 1000 women (a rate of less than 1%)1
1 World Health Organization Department of Reproductive Health and Research (WHO/RHR) and Johns Hopkins Bloomberg School of Public Health/Center for Communication Programs (CCP), INFO Project. Family Planning: A Global Handbook for Providers. Baltimore and Geneva: CCP and WHO, 2008.