Emergency contraception

Methods of post-coital contraception include:

1. Intrauterine device (IUD) – prevents fertilisation, and implantation
2. Oral emergency contraception – prevents or delays ovulation

Despite more than a decade of non-prescription availability of levonorgestrel, emergency contraception is currently under-utilised in Australia and elsewhere in the world.

Indications

1. Unprotected intercourse
2. Potential barrier method failure
3. Potential pill failure e.g. missed pills or vomiting

Oral Emergency Contraception

Levonorgestrel

• It is effective up to 4 days (96 hours) following unprotected sexual intercourse. Leveomorgestrol is only approved by TGA for use up to 72 hours following unprotected sexual intercourse.
• Not as effective as copper IUD or Ulipristal
• May be reduced effectiveness if BMI > 26kg/m2
• Able to recommence hormonal contraception immediately after use
• A replacement dose of levonorgestrel is recommended if vomiting occurs within 2 hours of administration

Ulipristal

• It is effective up to 5 days (120 hours) following unprotected sexual intercourse
• Most effective emergency contraception method
• May be reduced effectiveness if BMI > 30 kg/m2
• Do not commence hormonal contraception within 5 days of use
• If vomiting occurs within 3 hours of ulipristal ingestion, a replacement dose is recommended. ⁴

Note that all methods of emergency contraception are more effective the sooner they are started after unprotected sexual intercourse.

Intrauterine Device Emergency Contraception

Copper Intrauterine device:

• It is up to 99% effective
• It can be used up to 5 days (120 hours) following unprotected sexual intercourse
• Recommendation to use over oral options:
  • Elevated liver enzymes
  • Body mass index > 30kg/m2 or weight > 85kg
  • Preference for ongoing contraception

Levonorgestrel-releasing IUDs are not suitable for use as emergency contraception.

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References

FOAMed

Publications

• Randomised controlled trial of levonorgestrel versus the Yuzpe regimen of combined oral contraceptives for emergency contraception. Task Force on Postovulatory Methods of Fertility Regulation. Lancet. 1998 Aug 8;352(9126):428-33.
• Family Planning New South Wales, Family Planning Victoria, True Relationships and Reproductive Health. Contraception: An Australian clinical practice handbook. 4th ed. Ashfield, NSW. 2016.
• Family Planning Alliance Australia. Ulipristal acetate emergency contraception and breastfeeding. 2020.