Intrauterine System (IUS)

Question 1

Briefly describe the mechanim of action of the intrauterine system (IUS)

Answer 1

• The contraceptive effects of the levonorgestrel intrauterine system (LNG-IUS) are mainly due to its progestogenic effect on the endometrium, which prevents implantation of the fertilized ovum. In addition, changes in cervical mucus inhibit penetration of sperm into the uterus.
• More than 75% of women will continue to ovulate while using this method.

Question 2

What are the indications of IUS?

Answer 2

• Contraception
• Mennorhagia

Question 3

Once the IUS is in the uterus, what is released?

Answer 3

Levonorgestrel (a progestogen).

Question 4

What is the most common regime of IUS?

Question 5

What is the efficacy of IUS?

Answer 5

• Used perfectly→ 0.2% of women will conceive within the first year of use due to method failure
• Used typically→ 0.2% of women will conceive within the first year of use due to method failure

Question 6

What are the advantages of the IUS?

Answer 6

• Very safe and effective
• Long-term contraception (only needs replaced every 3 to 5 years)
• Sex need not be interrupted to use contraception
• Periods usually become lighter and shorter, and sometimes less painful
• The LNG-IUS can be used:
  
  • In women of any age, whether or not they have previously been pregnant
  • From 4 weeks postpartum
  • Immediately after surgical or medical termination of pregnancy
  • Whilst breastfeeding
  • Through the menopause
    When combined oral contraceptives (COCs) are contraindicated
• May reduce pain associated with primary dysmenorrhoea, endometriosis or adenomyosis

Question 7

What are the disadvantages of the IUS?

Answer 7

• An internal pelvic examination is needed to check that the LNG-IUS is suitable and to insert the device
  
  • There may be pain or discomfort for a few hours after insertion; this can be treated with analgesics such as paracetamol or ibuprofen.
• A trained healthcare provider must remove the device
• It does not protect against STIs
• The LNG-IUS may be expelled without the woman knowing
• Adverse effects (such as acne, headaches and unscheduled bleeding) may be experienced during the first 3–6 month of using the LNG-IUS

Question 8

What are the side effects of the IUS?

Answer 8

• Pain on insertion
• Acne
• Breast tenderness
• Headache
• Unscheduled bleeding
• Depression
• Weight gain
• Decreased libido
• Dizziness

Question 9

What are the risks of the IUS?

Answer 9

• Perforation of the wall of the uterus
• Expulsion
• Pelvic inflammatory disease (PID)
• Ectopic pregnancy
• Ovarian cysts

Question 10

Briefly describe how to assess a woman for the IUS

Answer 10

• Exclude pregnancy → if pregnancy is possible, do not insert IUS
• Check the UK Medical Eligibility Criteria
• Assess the woman’s risk of STIs
  
  • If appropriate, advise testing, promote safer sex and/or refer for sexual health counselling
• If the woman has unexplained vaginal bleeding that suggests an underlying medical condition (such as bleeding between her periods or after sexual intercourse)→ do not insert the LNG-IUS until the cause of bleeding has been diagnosed

Question 11

What are the contra-indication of the IUS?

Answer 11

• Infection: current pelvic inflammatory disease (PID) or purulent cervicitis, current symptomatic chlamydia or gonorrhoea, septic abortion or postpartum endometritis, pelvic tuberculosis
• Current pregnancy
• Some cancers: cervical cancer, endometrial cancer, malignant trophoblastic disease, current breast cancer
• Undiagnosed irregular vaginal bleeding/suspicion of genital malignancy

Question 12

How often does the IUS have to be replaced?

Answer 12

3-5 years (depending on the brand used)