Long term use of LNG-IUS (Mirena) and bone mineral density

Goodfellow Gems Logo

Goodfellow Gems

Long term use of LNG-IUS (Mirena) and bone mineral density

Long term use of LNG-IUS (Mirena) does not cause loss of bone mineral density (BMD) in women and is safe to use.

The Mirena IUS is fully funded in New Zealand. One case report1 reported low levels of oestrogen and loss of BMD in a 29-year-old woman who had had a Mirena in situ for 6 years.  There was speculation that the cause was disruption of the hypothalamic-gonadal axis.  Cohort studies have failed to support such a link.2,3 The Mirena works by prevention of implantation not suppression of ovulation. There is no contraindication to Mirena in women at risk of low BMD, e.g. with eating disorders.4

This Gem was written by Dr Orna McGinn, Clinical Director Primary Care Women’s Health, Auckland District Health Board.

References:

  1. Osteoporosis in a young woman after 6 years of levonorgestrel administration from intrauterine devices? BMJ Case Rep. (2009). View here
  2. Prospective study of the forearm bone mineral density of long-term users of the levonorgestrel-releasing intrauterine system. Human Reproduction (2010). View here
  3. Changes in Bone Mineral Density of Users of the Levonorgestrel-releasing Intrauterine System. Journal of Nippon Medical School (2012). View here
  4. FSRH CEU Statement: Contraception for Women with Eating Disorders (2018). View here

Gems are chosen by the Goodfellow director Dr. Bruce Arroll to be either practice changing or practice maintaining. The information is educational and not clinical advice.



As published in NZ Doctor 15/07/2020