Intra uterine contraceptive devices (IUCD)

IUS ‘Mirena’ coil– levanogestrel coated coil (NB the dose in the coil is much lower than that of the PoP

Mechanism of action

• All IUCDs are though to have some action as a foreign body, stimulating leukocytes and prostoglandin release by the endometrium, which possibly provide a contraceptive effect
• Progestogenic effects:
  • Thickening of the cervical mucus
  • thinning of the endometrium
  • (in some women) inhibition of ovulation

Pros and Cons

• Pros
  • >99% effective
  • Can last long term (commonly 5 years but can be much longer)
  • Dual license for treatment of menorrhagia (reduces pain/flow)
  • High rate of amenorrhea
  • Can be used also as the progestogenic component of HRT (for up to 4 years)
  • Fully reversible
• Cons
  • Requires specialist fitting
  • Early on, may cause irregular bleeding/side effects
  • ‘Lost threads’ – expulsion, malposition, perforation
  • ? PID
  • Ectopic pregnancy risk ?
  • ? Difficult to insert in nulliparous women (can be overcome with prostaglandin gel if need be)

Copper Coil

• Lasts 5-10 years
• Few problems or side effects
• Avoids hormone treatments

Mechanism

• Foreign body effect
• Direct toxicity of Cu to sperm
• Less sperm reach the upper genital tract
• Altered uterine/tubal fluid

Pros and Cons

• Pros
  • Lasts 5-10 years
  • Highly effective (>98%)
  • Fully reversible
  • Immediately effective
  • Also used for emergency contraception (very effective)
• Cons
  • Heavy, painful periods
  • Irregular bleeding
  • Require specialist fitting
  • Insertion risks e.g. perforation, infection
  • ‘lost threads’
  • Risk of ectopic pregnancy
  • ? Difficulty to insert in nulliparous women

Contraindications to IUCDs

• Absolute
  • Pregnancy
  • ? vaginal bleeding
  • Acute PID
  • Wilson’s disease/ CU allergy *
• Relative
  • PHx of ectopic pregnancy *
  • Cervical/Vaginal infection
  • Fibroids
  • Anaemia *
  • Menorrhagia *
  • Recent history of PID *
  • Valvular heart disease *
  • ? nulliparity *
  • Multiple partners *
  • Immunosuppressed (steroids/HIV/immunosuppression) *

* Does not apply to Mirena coil

Infection and the IUCD

• Coils do NOT CAUSE pelvic infection
  • Can make pre-existing infection worse
  • Highest risk 20 days post insertion- thereafter background risk
  • Treat prior to insertion if known

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