Date: 3 February 2013
Case Scenario: 21-year-old presents to the emergency department at 8am very distraught. She reports the condom broke last night during intercourse and requests the morning after pill.
Background: Each year here are more than 40 million aborted pregnancies worldwide. Primary prevention of pregnancy is advocated with induced abortion as the back up method.
The definition of emergency contraception (EC) is the use of a device or drug as an emergency measure after unprotected intercourse to prevent pregnancy. This method of preventing pregnancy only became effective in the 1960’s with the introduction of hormonal regimens.
The Yuzpe method (combination of estrogen and progestogen) became the popular method in the 1970’s. This was followed by other hormone treatments including progestogen only, anti-gonadotropin (danazol) and anti-progestins (mifepristone and ulipristal acetate).
A copper intrauterine device (IUD) is a non-hormonal option that can be inserted postcoital up to five days after the estimated time of ovulation. It can also be left in the uterus as a long-term contraceptive method.
- Combo estrogen/progestogen (Yuzpe)
- Progestogen only (levonorgestrel LNG/Plan B)
- Anti-gonadotropin (Danazol)
- Anti-progestins (mifepristone/Ru486 and ulipristal acetate/UPA)
- Intrauterine device (IUD)
Question: What is the best intervention for emergency contraception?
Reference: Cheng I, Che Y, Gulmezoglu AM. Interventions for emergency contraception. Cochrane Database of Systematic Reviews 2012, Issue 8.
- Population: Adult woman attending for emergency contraception after a single episode of unprotected intercourse
- Intervention: Several different emergency contraceptive medications
- Comparison: Placebo, no therapy, or alternative emergency contraceptive medication
- Outcome: Pregnancy, adverse events
Results: Mid or low dose Ru486 was significantly more effective than LNG in 11 trials. This was only a marginal difference when only the four high-quality studies were included (RR 0.70, 95% CI 0.49-1.01.
LNG given as a single dose of 1.5mg was just as effective as the more common 0.75mg BID in three trials (RR 0.84, 95% CI 0.53-1.33).
LNG was consistently better then Yuzpe method in five trials (RR 0.54, 95% CI 0.36-0.80).
UPA as a single oral dose showed no difference compared to LNG in two trials (RR 0.63, 95% CI:0.37 – 1.07).
Some of the medications caused nausea and vomiting and others affected menses. The side effects in all the studies were minor and there were no safety concerns.
Authors’ Conclusions: “Intermediate-dose mifepristone (25-50 mg) was superior to LNG and Yuzpe regimens. Mifepristone low dose (< 25 mg) may be more effective than LNG (0.75 mg two doses), but this was not conclusive. UPA may be more effective than LNG. LNG proved to be more effective than the Yuzpe regimen. The copper IUD was the most effective EC method and was the only EC method to provide ongoing contraception if left in situ.”
BEEM Commentary: This is a very large Cochrane systematic review and meta-analysis with excellent methodology as we can usually expect from Cochrane. This review included 100 studies with over 55,000 women. The majority of the studies were from China, but there were also some WHO multi-national studies that confirmed many of the findings.
BEEM Bottom Line: In Canada and USA if Plan A fails then Plan B (LNG) as a single dose of 1.5mg levonorgestrel.
The anti-progestins (Ru486 and UPA) are not currently available in Canada, but are apparently available in the US. The Yuzpe method is available in Canada but must be prescribed by a physician, is less effective than LNG, and therefore, should no longer be routinely used.
Since the introduction of LNG in Canada, the ED visits solely for Emergency Contraception has declined dramatically, but knowledge of the agents and their effectiveness is still important for Emergency Physicians.
Case Scenario Conclusion: The young woman was provided with information on her options including EC. The effectiveness and common side effects of EC were discussed. Shared decision making took place and you provide her with levonorgestrel (Plan B).
KEENER KONTEST: There were many Queen fans out there who got the Keener question right. Vanilla Ice sampled the song Under Pressure featuring David Bowie. The first correct answer was from Dr. Glen Armstrong from High Prairie, Alberta.
Be sure to listen to the podcast to hear this weeks Keener Kontest question. Email your answer to TheSGEM@gmail.com. Use “Keener Kontest” in the subject line. First one to email me the correct answer will win a cool skeptical prize.
This will be posted the day before starting SkiBEEM 2013. Look forward to seeing lots of TheSGEM listeners at the conference. The BEEM Team will be cutting that KT window down to less than one year.
Remember to be skeptical of anything you learn, even if you heard it on The Skeptics’ Guide to Emergency Medicine.