side effects/risks associated with use

Last reviewed 09/2023

• menstrual effects
  • during the first few months of use there is usually an increase in total number of bleeding days (menstrual bleeding plus intermenstrual bleeding plus spotting). If used for 3 months then there is generally a reduction in blood loss by more than 75% and a reduction in number of bleeding days. After 1 year, most women only bleed lightly for 1 day per month. After 1 year about 15% of women are amenorrhoeic
  • up to 60% of women stop using the IUS within 5 years (2)
    • most common reasons are unacceptable vaginal bleeding and pain, less common reason is hormonal (non-bleeding) problem
      
      
• pelvic inflammatory disease: less than 1% for women at low risk of STI
  
  
• no evidence that IUS use causes weight gain (2)
  
  
• any changes in mood and libido are similar whether using the IUS or IUDs, and the changes are small (2)
  
  
• may be an increased likelihood of developing acne as a result of absorption of progestogen, but few women discontinue IUS use for this reason (2)
  
  
• risk of uterine perforation at the time of IUS insertion is very low (less than 1 in 1000) (2)
  
  
• risk of developing pelvic inflammatory disease following IUS insertion is very low (less than 1 in 100) in women who are at low risk of STIs (2)
  
  
• IUS may be expelled, but this occurs in fewer than 1 in 20 women in 5 years (2)
  
  
• risk of ectopic pregnancy when using the IUS is lower than when using no contraception (2)
  
  
• overall risk of ectopic pregnancy when using the IUS is very low, at about 1 in 1000 in 5 years. If a woman becomes pregnant with the IUS in situ, the risk of ectopic pregnancy is about 1 in 20, and she should seek advice to exclude ectopic pregnancy (2)

Other side effects include:

• headaches, nausea, depression, acne

However note that the sytemic side-effects are rare with this particular coil because the dose of levonorgestrel absorbed systemically is small, equivalent to two progestogen-only-pills per week (1).

Reference:

1. Prescriber 2001; 12 (5): 83-95.
2. NICE (September 2014). Long-acting reversible contraception