Counsel women to take ECPs as soon as possible

Further analyses of a randomized, controlled trial of two different regimens of emergency contraceptive pills (ECPs) carry an important message for family planners: The earlier the treatment begins, the more effective it is.

Findings of a 21-center multinational randomized controlled trial published last year compared the Yuzpe ECP regimen of combined oral contraceptives with a progestin-only regimen using levonorgestrel.1 (Contraceptive Technology Update reported on the results of this study in the November 1998 issue. See pp. 143-145.)

This study indicated that in both study groups, the efficacy of both treatments declined with increasing time following unprotected intercourse. Researchers took a further look at their results and now have concluded that in either treatment regimen, delaying the first dose by 12 hours increases the odds of pregnancy by about 50%.2

"We looked at the pregnancy risk by 12-hour intervals and found that at each 12-hour interval, the risk increased by about 50%," confirms Helena von Hertzen, medical director with the Special Programme of Research, Development, and Research Training in Human Reproduction, a division of the World Health Organization (WHO) in Geneva, Switzerland, which coordinated the study. "This increase was linear and statistically significant."

Look at analyses

For its analyses, the researchers looked at both treatments together because there were too few cases for each 12-hour interval to draft two separate curves, von Hertzen says. The efficacy of both regimens appears to be highest when the treatment is taken within the first 12 hours, she notes.

"This finding supports the earlier finding from investigators in New Zealand, who reported that the Yuzpe regimen is more effective if taken within 12 hours than between 13 and 24 hours,"3 she notes. "In our study, the decrease in efficacy by delay appeared to be somewhat slower with levonorgestrel compared to the Yuzpe regimen."

Researchers will be able to clarify the timing of levonorgestrel-only ECPs further when a large multicenter trial is completed in early 2000, says von Hertzen. The study will include the experiences of about 2,800 women who have used the progestin-only regimen.

Because the WHO study shows that the Yuzpe regimen (and the levonorgestrel regimen as well) is more effective when taken in the first 12 hours after intercourse, with efficacy declining steadily in each 12-hour period thereafter, the first ECP dose should be taken as soon as possible, says James Trussell, PhD. Trussell is professor of economics and public affairs and associate dean of the Woodrow Wilson School of Public and International Affairs at Princeton (NJ) University. The timing of the second dose can be altered if taking it 12 hours later is impractical, he notes.

Trussell, who presented on ECP provision at the 1999 Contraceptive Technology conferences in San Francisco and Washington, DC, says this finding of decreasing effectiveness with increasing delay of treatment has two clinical implications: Advance provision of at least a prescription, if not of the ECPs themselves, is a terrific idea; and clinicians need to develop some mechanism for providing EC on the weekends.

"Having ECPs available from pharmacies, as in Washington [state], is a great solution," he says. (Read more about the project, which allows direct pharmacy provision of ECPs through collaborative agreements between pharmacists and providers, CTU, June 1998, pp. 79-80.)

Planned Parenthood Federation of America in New York City now allows its affiliates to prescribe ECPs over the telephone to all women, including nonpatients, if the provider obtains a medical history and informed consent before the prescription.

"It is extremely important, if prescribing ECPs (as contrasted with providing, which is definitely preferable), to know that the pharmacy to which you are sending your patient has the specific pill you are prescribing," says Robert A. Hatcher, MD, MPH, professor of OB/GYN at Emory University in Atlanta. "This is particularly important for Preven [Gynétics, Belle Mead, NJ] and Ovral [Wyeth-Ayerst Lab orator ies, Philadelphia], which a number of pharmacies do not have in stock."

Trussell advocates advance education when it comes to emergency contraception:

    • Provide information to women and men in a culturally sensitive manner during counseling.
    • Use posters, brochures, audio and videocassettes, and wallet cards to reinforce the message.
    • Advertise the availability of your emergency contraception services.
    • Be sure your receptionist and those who answer the telephone have correct EC information on hand.

An informal telephone survey of providers listed on the Emergency Contraception Web site ( and hotline (888-NOT-2-LATE) found that about 20% of those answering the telephone were unable to give information on EC, notes Trussell. Make sure your frontline people are prepared; give them a "FAQ" (frequently asked questions) sheet so they can correctly answer such calls, says Trussell.


    1. Task Force on Postovulatory Methods of Fertility Regulation. Randomised controlled trial of levonorgestrel versus the Yuzpe regimen of combined oral contraceptives for emergency contraception. Lancet 1998; 352:428-433.

    2. Piaggio G, von Hertzen H, Grimes DA, et al. Timing of emergency contraception with levonorgestrel or the Yuzpe regimen. Task Force on Postovulatory Methods of Fertility Regulation. Lancet 1999; 353:721.

    3. Kane LA, Sparrow MJ. Postcoital contraception: A family planning study. NZ Med J 1989; 102:151-153.