- Less than 1 pregnancy per 100 women using an LNG-IUD over the first year (2 per 1,000 women). This means that 998 of every 1,000 women using LNG-IUDs will not become pregnant.
- A small risk of pregnancy remains beyond the first year of use and continues as long as the woman is using the LNG-IUD.
- Over 5 years of use of the Mirena LNG-IUD: Less than 1 pregnancy per 100 women (5 to 8 per 1,000 women).
- Mirena and Kyleena are approved for up to 5 years of use. Research suggests that Mirena may remain highly effective for up to 7 years. Liletta, Skyla, and Jaydess are approved for up to 3 years of use.
Return of fertility after LNG-IUD is removed: No delay
Protection against sexually transmitted infections (STIs): None