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RHO archives : Topics : Contraceptive Methods

Emergency Contraception

Overview

Emergency contraception is a form of contraception that women can use to prevent pregnancy after unprotected intercourse (such as when a contraceptive fails or when sex occurs without contraception). Two types of emergency contraception are available: emergency contraceptive pills (ECPs) and emergency copper-bearing IUD insertion. ECPs can be used up to 72 hours (three days) after unprotected intercourse; emergency IUD insertion can be used up to five days after unprotected intercourse (Glasier 1998).  Both methods are safe and effective if proper service delivery guidelines are followed. The only condition restricting use of ECPs is established pregnancy. Conditions restricting regular use of IUDs also apply to their emergency use.

ECPs have been available since the 1960s, but service delivery protocols were not standardized, many providers did not know about this method, and access has been limited. The safety and effectiveness of ECPs has been well documented (ACOG 1996; Trussell 1996; Van Look 1996). In the past five years, a consortium of international organizations, including the World Health Organization (WHO), have worked to make emergency contraception more widely available and to increase the knowledge of providers and consumers about this method (FHI 2001).

Increasing awareness of and access to emergency contraception is one critical way to improve the health and well-being of all women, including adolescents, by preventing unintended pregnancy and abortion (Beitz and Hutchings 2002). For example, a recent WHO study found that 60 percent of induced abortions in Shanghai, China, could have been prevented if women had used levonorgestrel-only ECPs. Despite the important role emergency contraception can play in reducing unintended pregnancy and decreasing abortion rates, there is a significant knowledge gap among both health care professionals and users (Beitz and Hutchings 2002).

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ECPs: Administration and side effects

Yuzpe regimen

Developed in the 1970s, the Yuzpe regimen of emergency contraception uses pills that contain both estrogen and progestin (100 mcg of ethinyl estradiol and 0.50 mg levonorgestrel). It is taken in two doses: (1) two pills taken within 72 hours of unprotected intercourse, and (2) a second dose of two pills 12 hours later. Until recently, the Yuzpe regimen of combined oral contraceptive pills was the only hormonal method available for emergency contraception. An analysis of eight studies of the effectiveness of the combined regimen concluded that the Yuzpe regimen prevents about 74 percent of expected pregnancies (Trussell 1999).

Progestin-only, two-dose regimen

In an effort to reduce side effects such as nausea, vomiting, and headaches (primarily caused by estrogen), researchers in the 1990s studied the efficacy of progestin-only pills for emergency contraception. In a large, multi-center clinical trial, WHO researchers found that a regimen using two 0.75 mg doses of levonorgestrel administered 12 hours apart, taken up to 72 hours after unprotected intercourse, is better tolerated and more effective than the Yuzpe regimen (WHO 1998; PATH/Outlook 1999). The regimen prevents about 85 percent of expected pregnancies if initiated within 72 hours after intercourse. The two-dose regimen of levonorgestrel pills has been approved in more than 80 countries. WHO researchers suggest that the progestin-only emergency contraception regimen replace the Yuzpe regimen because it is more effective and causes fewer side effects. (For additional information, see JHPIEGO 2003.)

Progestin-only, one-dose regimen

Recently, a WHO study found that a single 1.5 mg dose of levonorgestrel can substitute for two 0.75 mg doses 12 hours apart. Both regimens are considered very effective at preventing pregnancy (Von Hertzen 2002). This finding should simplify ease of use for women needing emergency contraception without an increase in side effects. Although women are counseled to begin treatment within 72 hours, the regimens studied prevented a high proportion of pregnancies even up to 5 days after unprotected intercourse.

Side effects

The main side effects of ECP treatment are nausea and vomiting. Side effects are more common with combined (Yuzpe) ECP regimens than with progestin-only ECP regimens. About half of women taking combined ECPs experience nausea, and up to one-fifth vomit after the first or second dose. Rates of nausea and vomiting are 20 percent and 5 percent, respectively, in women using progestin-only regimens. These side effects generally do not last more than 24 hours, and may be reduced in some women by providing anti nausea medication before ECP treatment.

Taking ECPs

Both the levonorgestrel-only regimen and the Yuzpe regimen are available in some locations as products formulated and labeled specifically for use as ECPs. In locations where a dedicated product is not available, ECP packets can be made from regular oral contraceptive pills (see table below).

Treatment should be initiated as soon as possible. Research indicates that efficacy declines substantially over time.

For information about dedicated products available worldwide, please see the Consortium for Emergency Contraception website (www.cecinfo.org/html/res-product-issues.htm).

For Information about products available from U.S. manufacturers, see the table below:


Brand/Manufacturer


Pills per Dose*


Ethinyl Estradiol per Dose (mcg)


Levonorgestrel per Dose (mg)**

Dedicated Products

Preven (Gynetics)

2 blue pills

100

0.50

Plan B (WCC)

1 white pill

0

0.75

Oral Contraceptive Pills

Ovral (Wyeth-Ayerst)

2 white pills

100

0.50

Alesse (Wyeth-Ayerst)

5 pink pills

100

0.50

Levlite (Berlex)

5 pink pills

100

0.50

Nordette (Wyeth-Ayerst)

4 light- orange pills

120

0.60

Levlen (Berlex)

4 light- orange pills

120

0.60

Levora (Watson)

4 white pills

120

0.60

Lo/Ovral (Wyeth-Ayerst)

4 white pills

120

0.60

Triphasil (Wyeth-Ayerst)

4 yellow pills

120

0.50

Tri-Levlen (Berlex)

4 yellow pills

120

0.50

Trivora (Watson)

4 pink pills

120

0.50

Ovrette (Wyeth-Ayerst)

20 yellow pills

0

0.75

* The treatment schedule is one dose within 72 hours after unprotected intercourse, and a second dose 12 hours later.
** The progestin in Ovral, Lo/Ovral, and Ovrette is norgestrel, which contains two isomers, only one of which (levonorgestrel) is bioactive; the amount of norgestrel in each dose is twice the amount of levonorgestrel.

Tables adapted from Journal of the American Medical Women's Association, EC Supplement 1998, revised version of the table (page 213).

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Characteristics of ECPs

Effectiveness

Effectiveness of ECPs ranges from approximately 74% to 85%, depending on the regimen used and when treatment is initiated. (Note: this failure rate cannot be compared directly to annual failure rates of other methods because it is for a single use.)

Age limitations

No restrictions on use

Parity limitations

No restrictions on use for nulliparous or parous women

Mode of action

Primarily by inhibiting ovulation; treatment also may cause changes in the endometrium

Effect on STI risk

Not protective

Drug interaction

None known; given the short duration of treatment it is unlikely that drug interactions that affect COC use also affect ECP use

Duration of use

Intended for occasional "emergency" use; other methods used correctly and consistently provide more effective ongoing contraceptive protection

Return to fertility

Immediate; therefore, it is critical that women begin using another form of contraception immediately after use

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Copper IUD

The most effective method of emergency contraception is the insertion of a copper IUD. If inserted within five days of unprotected intercourse, the copper IUD prevents pregnancy in 99 percent of cases.

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Medical and service delivery guidelines

Offering emergency contraception can improve services and allow family planning programs to better meet the needs of clients. The Consortium for Emergency Contraception has compiled service delivery guidelines to give family planning and reproductive health programs the information they need to provide ECPs safely and effectively. The recommendations in these guidelines reflect the latest research on emergency contraception and can be adapted by local organizations to comply with national or other requirements. The service delivery guidelines are available at the consortium website (www.cecinfo.org/files/Medical-Service-Delivery-Gdelines.pdf).

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Increasing access

Several efforts are underway to help providers understand the service-delivery implications of providing emergency contraception and increase overall access to ECPs (Consortium for Emergency Contraception 1997; Population Council 1999; PATH/Outlook 1996). Key issues of interest include the following:

  • whether making ECPs more widely available will serve as an effective bridge to regular contraceptives;
  • what level of health care provider can dispense ECPs;
  • whether advanced distribution of ECPs will encourage nonuse of regular family planning methods;
  • whether additional pill formulations also are effective as ECPs;
  • how to reduce barriers to access; and how to best reach women and service providers with information about ECPs.

In Washington State, United States, pharmacist prescription of ECPs is being evaluated as a method of improving access to services (PATH 1999).

Can use of emergency contraception reduce the number of abortions?

By preventing unintended pregnancies, emergency contraception can reduce the need for abortion. A recent study by the Alan Guttmacher Institute of contraceptive use among U.S. women having an abortion found that a substantial proportion of the 11 percent decline in abortion rates between 1994 and 2000 resulted from womens use of emergency contraception (Jones et al. 2002). In developing countries where abortion remains illegal, unsafe abortion is a leading cause of death among women of reproductive age. Unsafe abortions are a drain on scarce medical resources. In settings such as these, emergency contraception could prevent deaths and reduce pressure on limited health resources (Consortium for Emergency Contraception 2000).

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