Face facts about effectiveness of ECPs
In 1992, reproductive health advocates estimated that emergency contraceptive pills (ECPs) could prevent half of all unintended pregnancies and abortions in the United States each year.1 Today, two analyses of available data show that advance provision of emergency contraceptive pills enhances use but has not been shown to reduce unintended pregnancy rates.2-3 This finding comes in light of the fact that one demonstration project4 and three clinical trials5-7 were specifically designed to address this issue.
What do the new analyses mean for family planners?
"Be honest with women when discussing ECPs: Do not oversell by implying Plan B will reduce unintended pregnancy," says James Trussell, PhD, professor of economics and public affairs and director of the Office of Population Research at Princeton (NJ) University and a co-author of one of the current analyses. Trussell presented data on the subject at the recent Contraceptive Technology conference in San Francisco and Washington, DC.
However, clinicians should not give up on the method, because ECPs do work, he says. While advance provision of ECPs does not reduce unintended pregnancy on a population level, it does not have any harmful effects. Analyses of the research show that increased access does not:
- increase rates of sexually transmitted infections;
- decrease condom use;
- encourage adoption of less reliable contraceptive methods;
- otherwise negatively affect sexual and reproductive behavior.2
"Conclusions about population-level effects should not impede efforts to ensure all women have access to emergency contraception when they need it," states one of the analyses.3 "Women should be given information on and easy access to emergency contraception because individual women can decrease their chances of pregnancy by using the method."
Why didn't pregnancies decrease with advance provision? Trussell points to three examples:
- In a San Francisco study, almost half of the women in the advance provision group who had unprotected intercourse did not use ECPs.5
- In a Chinese study, 30 of the 38 pregnancies in the advance provision group occurred in women who did not use ECPs in that cycle.6
- In a Nevada/North Carolina study, 57 of the 74 pregnancies in the advance provision group occurred in women who did not use ECPs in that cycle.7
The lesson? "ECPs are not used frequently enough," Trussell says.
Check ABCs of ECPs
There are two types of emergency contraceptive pills: combined ECPs, which are ordinary birth control pills containing estrogen and progestin, and progestin-only pills. The hormones that have been studied the most in clinical trials of ECPs are ethinyl estradiol and levonorgestrel or norgestrel.8 Such hormone combinations are found in 22 brands of combined oral contraceptives available in the United States.
The only progestin-only product available in the United States is Plan B (marketed by Duramed, a subsidiary of Barr Pharmaceuticals; Pomona, NY). It was originally approved by the Food and Drug Administration (FDA) in July 1999 as a prescription-only drug; on Aug. 24, 2006, the FDA approved the nonprescription sale of Plan B for women and men 18 and older. Younger women still need a prescription to buy the drug, and it is sold from behind the pharmacy counter, not the shelf.
Use of Plan B continues to climb. Barr Labs sold $11.8 million in Plan B prescriptions in the first six months of 2006, up 41% from the previous year, according to IMS Health, a health care information company.9
What about use of the intrauterine device (IUD) for emergency contraception? The copper-T IUD (ParaGard, marketed by Duramed, a subsidiary of Barr Pharmaceuticals; Pomona, NY) can be inserted up to the time of implantation — five to seven days after ovulation — to prevent pregnancy.8 Due to the difficulty in determining the day of ovulation, many protocols allow insertion up to only five days after unprotected intercourse.8
Much more emphasis should be placed on the EC use of the IUD, says Robert Hatcher, MD, MPH, professor of obstetrics and gynecology at Emory University in Atlanta. Not only does the woman avoid unintended pregnancy, but she is protected against such risks for up to 10 years, he notes.
According to Hatcher, two important conclusions may be drawn from the recent analyses:
- When a woman and a man do not want to become pregnant, they must make a commitment to never have intercourse without contraception. "This commitment is an 'inside job'; no contraceptive delivery system is as important as a commitment from individuals not to take chances," Hatcher observes.
- All providers of emergency contraception must begin to stress that insertion of a copper-T IUD as an emergency contraceptive is preferable for most women than use of ECPs.
References
- Trussell J, Stewart F, Guest F, et al. Emergency contraceptive pills: A simple proposal to reduce unintended pregnancies. Fam Plann Perspect 1992; 24:269-273.
- Raymond EG, Trussell J, Polis CB. Population effect of increased access to emergency contraceptive pills: A systematic review. Obstet Gynecol 2007; 109:181-188.
- Polis CB, Schaffer K, Blanchard K, et al. Advance provision of emergency contraception for pregnancy prevention (full review). Cochrane Database Syst Rev 2007; 2:CD005497.
- Glasier A, Fairhurst K, Wyke S, et al. Advanced provision of emergency contraception does not reduce abortion rates. Contraception 2004; 69:361-366.
- Raine TR, Harper CC, Rocca CH, et al. Direct access to emergency contraception through pharmacies and effect on unintended pregnancy and STIs: A randomized controlled trial. JAMA 2005; 293:54-62.
- Hu X, Cheng L, Hua X, et al. Advanced provision of emergency contraception to postnatal women in China makes no difference in abortion rates: Randomized controlled trial. Contraception 2005; 72:111-116.
- Raymond EG, Stewart F, Weaver M, et al. Impact of increased access to emergency contraceptive pills: A randomized controlled trial. Obstet Gynecol 2006; 108:1,098-1,106.
- Trussell J, Raymond EG. Emergency Contraception: A Cost-Effective Approach to Preventing Unintended Pregnancy. Accessed at: ec.princeton.edu/questions/ec-review.pdf.
- Henderson D. FDA approves sale of 'morning-after' pill. Boston Globe, Aug. 25, 2006: accessed at: www.boston.com.
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