Mirena IUD Side Effects and Complications

The Mirena IUD was originally approved for contraceptive use in 2000. In January 2010, the FDA approved the use of Mirena for the treatment of heavy menstrual bleeding in women who have given birth. The Mirena IUD is the only intrauterine device currently approved for this indication. Mirena is indicated for intrauterine contraception for up to 5 years. At that point, the system should be replaced if continued contraception is desired. Mirena is only recommended for women who have had at least one child.

Mirena consists of a T-shaped polyethylene frame (Tbody) with a steroid reservoir (hormone elastomer core) around the vertical stem. The steroid reservoir contains the progestogen levonorgestrel, which is secreted slowly into the uterus over time upon the insertion of Mirena by a trained healthcare provider.

Since its approval, serious Mirena side effects have included ectopic pregnancy, intrauterine pregnancy (a pregnancy in the uterus with the IUD in place), group A streptococcal sepsis, pelvic inflammatory disease (PID), embedment of the device in the uterine wall, and perforation of the uterine wall or cervix. Other common Mirena side effects include irregular spotting or bleeding, headaches, ovarian cysts, vaginitis, painful menstruation, pelvic pain, and breast tenderness.

In June 2010, the Canadian regulatory agency, Health Canada, reminded healthcare providers there of important safety information regarding reports of uterine perforation in women using Mirena. According to Health Canada, Bayer Inc. continues to receive post-market reports of uterine perforation associated with the use of Mirena.

According to Health Canada, some cases of Mirena uterine perforation were not detected during or immediately after the insertion. The risk of perforation may be increased with use in the post-partum period, during lactation, and in women with an atypical uterine anatomy (such as fixed retroverted uterus). Uterine perforation may occur with Mirena at the time of insertion or after the insertion with limited clinical symptoms, Health Canada said.