emergency contraception

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Emergency Contraception



Emergency contraception or emergency birth control uses either emergency contraceptive pills (ECPs) or a Copper-T intrauterine device (IUD) to help prevent pregnancy following unprotected vaginal intercourse.


Emergency contraception may be used to prevent pregnancy after vaginal intercourse when:
  • A birth control method was not used. Young people, in particular, may not be prepared for their first experience of sexual intercourse.
  • A condom broke or slipped and ejaculation occurred within the woman's vagina.
  • The male failed to withdraw from the vagina before ejaculation.
  • A woman failed to take her birth control pills.
  • A diaphragm, cap, or shield slipped out of place, followed by ejaculation within the vagina.
  • A woman's "safe days" were miscalculated.
  • A woman was raped or otherwise forced to have unprotected intercourse.
Women who missed taking their oral contraceptives may consider emergency contraception if:
  • A new packet of pills was started at least two days late.
  • Two to four of the first seven active (hormone-containing) pills (days 1-7) were missed.
  • Five or more active pills were missed consecutively.
On average eight out of every 100 fertile women will become pregnant after having one episode of unprotected vaginal intercourse during the second or third week of their menstrual cycle. Following treatment with combined ECPs, only two of those 100 women will become pregnant—a 75% reduction. Following treatment with progestin-only ECPs, only one woman out of the 100 will become pregnant—an 89% reduction. Following emergency insertion of an IUD there is a 99.9% reduction in the risk of pregnancy.


Emergency contraception does not work after the onset of pregnancy; nor should it be used as a regular method of birth control. ECPs do not prevent pregnancy from intercourse that occurs following the treatment; another birth control method must be used to prevent pregnancy. Although ECPs will not affect an existing pregnancy and will not harm the fetus, emergency contraception should not be used if a woman is already pregnant.
Frequent use of ECPs can result in irregular or unpredictable menstrual periods. Additional doses of ECPs usually do not reduce the risk of pregnancy and they increase the risk of side effects including nausea and vomiting.
Almost all women can use emergency contraception safely, even those who cannot use oral contraceptives as a regular method of birth control because of heart disease, blood clots, stroke, or other cardiovascular problems. The anti-convulsive medication Dilantin may reduce the effectiveness of ECPs. Some physicians recommend doubling the first of the two ECP doses if taken with Dilantin.
Progestin-only ECPs (POPs) are not recommended for women who:
  • may be pregnant already
  • have a hypersensitivity to any component of the medication
  • have abnormal, undiagnosed genital bleeding.
Copper-T IUDs should not be used for emergency contraception if a woman:
  • is pregnant
  • has a history of pelvic inflammatory disease (PID) that has impaired her fertility
  • has one of numerous other conditions affecting her reproductive system
  • has—or is currently at risk for contracting—a sexually transmitted disease (STD) such as HIV/AIDS, chlamydia, or gonorrhea, since IUD insertion can introduce infectious agents into the sterile uterine cavity.
Those at risk for contracting an STD include women who:
  • have been raped
  • have had unprotected sex with a new partner
  • are in a non-monogamous relationship
  • use intravenous drugs
  • have partners who use intravenous drugs


Although emergency contraception—sometimes called post-coital or morning-after contraception—has been available for over a quarter of a century, almost one-half of the 6.3 million pregnancies in the United States each year are unintended. Among teen pregnancies 80% are unintentional. About one-half of unintended pregnancies are caused by contraceptive failure, either a failure of the method or a mistake by the user. The remainder of unintended pregnancies occurs because birth control was not employed. Emergency contraception could help prevent some of the 1.4 million abortions that take place in the United States every year.
Emergency contraception prevents pregnancy by one of the following methods:
  • delaying or inhibiting ovulation—the release of eggs from the ovary
  • altering the transport of the sperm or egg, thereby preventing fertilization of the egg by a sperm
  • altering the endometrium or uterine lining, thereby preventing implantation—the attachment of the fertilized egg to the wall of the uterus
The mechanism by which ECPs prevent pregnancy depends on the stage of the woman's menstrual cycle. In most cases ECPs delay or inhibit ovulation and have no effect on implantation. IUDs used as emergency contraception appear to interfere with implantation of the fertilized egg; although they also may prevent fertilization, as they are thought to do when they are used as a regular method of birth control.

Emergency contraceptive pills (ecps)

ECPs contain synthetic hormones that mimic the hormones produced by a woman's body. Many common brands of birth control pills can be used for emergency contraception even though they are not labeled for that use. Any of the first 21 pills in a regular 28-pill package of oral contraceptives can be used for emergency contraception. The last seven pills in 28-pill packs do not contain hormones. The number of pills that constitute an emergency contraceptive dose depends on the brand of pill. The same brand should be used for both doses of ECPs. Many ECPs are available outside of the United States, where they are packaged, labeled, and sold for emergency contraceptive purposes.
COMBINED ECPS. Combined ECPs available in the United States contain 100 micrograms of the synthetic estrogen, ethinyl estradiol, and 0.5-0.6 mg of the synthetic progestin levonorgestrel per dose. Combined ECPs are taken according to the Yuzpe Regimen, named after A. Albert Yuzpe, the Canadian researcher who first demonstrated their safety and effectiveness in 1974. With the Yuzpe Regimen, the first dose of combined ECPs is taken as soon as possible after unprotected intercourse and the second dose is taken 12 hours later. However the timing of the second dose can vary by a few hours without diminishing its effectiveness. The Preven Emergency Contraceptive Kit—the first product to be specifically labeled and marketed for emergency contraception—is no longer available.
Combined ECPs available in the United States include:
  • Alesse, manufactured by Wyeth-Ayerst; five pink pills per dose
  • Aviane, manufactured by Duramed; five orange pills per dose
  • Cryselle, manufactured by Barr; four white pills per dose
  • Enpresse from Barr; four orange pills per dose
  • Lessina from Barr; five pink pills per dose
  • Levlen from Berlex; four light orange pills per dose
  • Levlite from Berlex; five pink pills per dose
  • Levora from Watson; four white pills per dose
  • Lo/Ovral from Wyeth-Ayerst; four white pills per dose
  • Low-Ogestrel from Watson; four white pills per dose
  • Lutera from Watson; five white pills per dose
  • Nordette from Wyeth-Ayerst; four light orange pills per dose
  • Ogestrel from Watson; two white pills per dose
  • Ovral from Wyeth-Ayerst; two white pills per dose
  • Portia from Barr; four pink pills per dose
  • Seasonale from Barr; four pink pills per dose
  • Tri-Levlen from Berlex; four yellow pills per dose
  • Triphasil from Wyeth-Ayerst; four yellow pills per dose
  • Trivora from Watson; four pink pills per dose
PROGESTIN-ONLY ECPS. Progestin-only ECPs (POPs) are prescribed frequently, particularly for women who cannot take estrogen or who are breastfeeding. POPs contain 0.75 mg of levonorgestrel per dose. They are equally effective regardless of whether the two doses are taken simultaneously or 12-24 hours apart. POPs are most effective if taken within 72 hours of unprotected intercourse; however they reduce the risk of pregnancy if taken within 120 hours.
Progestin-only pills include:
  • Plan B from Barr is the only drug available in the United States that is specifically designed and designated as an ECP—one white pill per dose.
  • Ovrette from Wyeth-Ayerth requires swallowing 20 yellow pills for each dose.

The copper-t iud

The Copper-T 380A IUD (ParaGard) is a T-shaped device that provides emergency contraception if inserted into the uterus by a healthcare provider within seven days after unprotected intercourse. It can be removed by the healthcare provider after the woman's next menstrual period begins or it can remain in place for up to 10-12 years as an effective method of birth control.


In most of the United States, emergency contraception requires a special prescription or a prescription for a monthly supply of an appropriate oral contraceptive. Most physicians do not routinely discuss the use of emergency contraception with their patients and some pharmacies refuse to carry ECPs.
Emergency contraception is available from:
  • public and college health clinics
  • women's health centers
  • Planned Parenthood clinics
  • private doctors
  • hospital emergency rooms, except those affiliated with a religion that opposes the use of birth control
  • pharmacists directly, in a small number of states.
Some healthcare providers may prescribe ECPs over the telephone. Sexual assault victims may be offered ECPs in the hospital emergency room.
In many countries ECPs are available without a prescription. However in the United States emergency contraception remains controversial. In September of 2004, the U. S. Department of Justice released guidelines for the treatment of sexual assault victims without mentioning the option of emergency contraception. As of early 2005, the U.S. Food and Drug Administration (FDA) had delayed approval of over-the-counter (OTC) status for Plan B. However many professional healthcare organizations and advocacy groups for women's reproductive rights were working to make ECPs available without a prescription in the United States.


The cost of emergency contraception varies greatly according to region and location and any additional required services. Family-planning clinics and public healthcare centers may provide lower-cost emergency contraception or charge according to an income-based sliding scale.
As of 2005, estimated costs for emergency contraception were:
  • $8-$35 for Plan B
  • $20-$50 for combined ECPs
  • $50-$70 for other progestin-only ECPs
  • $35-$150 for a visit to a healthcare provider
  • $10-$20 for a pregnancy test
  • about $400 for an exam, IUD, and insertion; however the IUD can remain in place for up to 12 years.


For emergency contraception to be effective, it must be used as soon as possible following unprotected intercourse. Some healthcare providers and women's health centers prescribe or supply packets of ECPs—called EC-to-Go—so that they are available immediately if required. Supplies of ECPs are particularly important for women who are at high risk for having unprotected intercourse. EC-to-Go also avoids the cost of an extra visit to a healthcare provider.
Studies have found that neither the use of ECPs, nor having a supply of ECPs on hand, reduce the likelihood that women, including teenagers, will use conventional contraceptive methods. In fact it has been shown that the use of ECPs often increases the likelihood that a regular birth control method will be employed.
If an office visit is required, a healthcare provider may take a medical history, perform a pregnancy test on a urine sample, and—provided that pregnancy has not occurred—discuss the appropriate type of emergency contraception.


For about 10-15% of women who take ECPs, the timing, duration, and/or amount of bleeding for their next menstrual period may be different than usual. About 50% of women have their first post-ECP menstrual period one to three days earlier or later than expected. Most often it is earlier than expected. Bleeding may be normal or heavier, lighter, or more spotty than usual.
Following IUD insertion, a woman may need to be escorted or driven home and she may require rest.


Emergency contraception is considered to be both safe and effective for teenagers as well as adult women. However emergency contraception may not prevent an ectopic pregnancy—a pregnancy outside of the uterus, in the fallopian tubes or abdomen. Ectopic pregnancies are medical emergencies and can be fatal.

Side effects of ecps

About 50% of women feel sick to their stomachs for approximately 24 hours after taking combined ECPs. Nausea occurs in 30-50% of women and 15-25% of women experience vomiting. Only 23% of women who take progestin-only ECPs experience nausea and only 6% have vomiting.
If vomiting occurs within one hour of taking ECPs, the dose may have to be repeated. OTC medications such as Dramamine II, Bonine, or their generic equivalents, taken one hour before the ECPs, reduce the risk of nausea and vomiting, although they may cause drowsiness. Two 25-mg tablets of Meclizine, taken one hour before the ECPs, reduce the risk of nausea by 27% and the risk of vomiting by 64%; however there is about a 30% risk of drowsiness. If vomiting occurs after the first dose of an ECP, antinausea medication should be taken one hour before the second dose. The second dose also may be taken as a vaginal suppository by placing the pills as far as possible into the vagina for absorption through the vaginal tissue.
Other side effects of ECPs can include:
  • breast tenderness
  • abdominal pain
  • irregular bleeding
  • dizziness
  • headaches
  • fatigue.
Side effects usually last only one to two days and are far less frequent with progestin-only ECPs as compared with combined ECPs.

Side effects of iud insertion

Side effects of IUD insertion may include:
  • abdominal discomfort
  • vaginal bleeding or spotting
  • infection.
However the risk of pelvic infection is very small among women who are not at risk for STDs.
Other possible side effects of IUD insertion include:
  • heavy menstrual flow
  • cramping
  • infertility
  • uterine puncture.

Normal results

The effectiveness of emergency contraception depends both on the stage of the woman's menstrual cycle and on how soon the emergency contraception is used following unprotected vaginal intercourse. The closer a woman is to ovulation—her fertile period during which eggs are released from the ovary—the less effective emergency contraception will be.
ECPs are less effective than the most popular birth control methods:
  • If taken within 72 hours of unprotected intercourse, combined ECPs are about 75% effective for preventing pregnancy.
  • Progestin-only ECPs are 95% effective if taken within 24 hours of unprotected intercourse and about 89% effective if taken within 72 hours.
  • A Copper-T IUD is 99.9% effective if inserted within seven days of unprotected intercourse.

Key terms

Emergency contraceptive pills; ECPs — Medication containing synthetic hormones for preventing pregnancy after unprotected vaginal intercourse.
Endometrium — The lining of the uterus.
Ethinyl estradiol — A semi-synthetic derivative of estradiol—an estrogen or female sex hormone—used in birth control pills and combined ECPs.
Implantation — The embedding of a fertilized egg in the inner wall of the uterus.
Intrauterine device; IUD — A device inserted into the uterus to prevent pregnancy.
Levonorgestel — A synthetic progestin used in ECPs.
Ovulation — The discharge of an ovum (egg) from the mature follicle of the ovary.
Progestin — A synthetic or natural drug that acts on the uterine lining.
Yuzpe Regimen — A two-dose treatment with combined ECPs to prevent pregnancy after unprotected intercourse; the first dose is taken as soon as possible and the second dose is taken 12 hours after the first.
If a normal menstrual period does not begin within three weeks after taking ECPs, or if signs of pregnancy develop, a healthcare provider should be consulted immediately.
Signs of pregnancy include:
  • a missed menstrual period
  • nausea
  • unexplained fatigue
  • enlarged or sore breasts
  • headaches
  • frequent urination
The majority of women express satisfaction with emergency contraception. One study of 235 women who had used ECPs found that 91% were satisfied with the method and 97% would recommend it to others.



Emergency Contraception: A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References. Icon Health Publications, 2004.
The Essential Guide for Emergency Contraception. American Healthcare Consultants, 2004.


Brody, Jane E. "The Politics of Emergency Contraception." New York Times August 24, 2004: F.7.
Cantor, Julie, and Ken Baum. "The Limits of Conscientious Objection—May Pharmacists Refuse to Fill Prescriptions for Emergency Contraception?" New England Journal of Medicine 351, no. 19 (November 4, 2004): 2008–12.
Raine, Tina R., et al. "Direct Access to Emergency Contraception Through Pharmacies and Effect on Unintended Pregnancy and STIs." Journal of the American Medical Association 293, no. 1 (January 5, 2005): 54-62.
Weismiller, David G. "Emergency Contraception." American Family Physician 70, no. 4 (August 15, 2004): 707-14.


Association of Reproductive Health Professionals. 2401 Pennsylvania Avenue NW, Suite 350, Washington, DC 20037. 202-466-3825. http://arhp.org.
The Emergency Contraception for Diverse Communities Project, Program for Appropriate Technology in Health (PATH). 1455 NW Leary Way, Seattle, WA 98107-5136. 206-285-3500. http://www.path.org.
National Women's Health Information Center, Office on Women's Health, U.S. Department of Health and Human Services. 8550 Arlington Blvd., Suite 300, Fairfax, VA 22031. 800-994-WOMAN (9662). http://www.4woman.gov.
Office of Population Research, Princeton University. Wallace Hall, Princeton, NJ 08544. 609-258-4870. http://opr.princeton.edu.
Planned Parenthood Federation of America, Inc. 434 West 33rd Street, New York, NY 10001. 800-230-7562 (PLAN). http://www.plannedparenthood.org.
U.S. Food and Drug Administration. 5600 Fishers Lane, Rockville MD 20857-0001. 888-INFO-FDA (888-463-6332). http://www.fda.gov.


Emergency Contraception. Planned Parenthood. February 2005 [cited March 6, 2005]. http://www.plannedparenthood.org/pp2/portal/medicalinfo/ec/pub-emergency-contraception.xml.
Emergency Contraception. Planned Parenthood. June 2004 [cited March 6, 2005]. http://www.plannedparenthood.org/pp2/portal/medicalinfo/ec/fact-emergency-contraception.xml.
Frequently Asked Questions About Emergency Contraception. The National Women's Health Information Center. November 2002 [cited March 6, 2005]. http://www.4woman.gov/faq/econtracep.htm.
Not-2-Late.com. The Emergency Contraception Website. Office of Population Research, Princeton University and the Association of Reproductive Health Professionals. [Cited March 6, 2005]. http://ec.princeton.edu.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.

emergency contraception

Measures taken to reduce the risk of pregnancy within a few days after sexual intercourse during which contraceptives failed or were not used. Forms of emergency contraception include oral drugs such as levonorgestrel and insertion of a copper intrauterine device.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

emergency contraception

A popular term for secondary “contraception” used in the event of failure or suboptimal “primary contraception”.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

emergency contraception

Morning after pill Gynecology The use of 2º contraception in the event of failure or suboptimal 1º contraception. See RU 486. Cf Back-up contraception.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

emergency contraception

Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
References in periodicals archive ?
(136.) Belzer M, Sanchez K, Olson J, Jacobs AM, and Tucker D (2005), "Advance Supply of Emergency Contraception: A Randomized Trial in Adolescent Mothers," J Pediatr Adolesc Gynecol.
Should girls under seventeen be able to buy it without prescription?--its availability shows how much the landscape of emergency contraception in the US has changed.
Interventions for emergency contraception. Cochrane Database Syst Rev.
Some supported the availability of emergency contraception for teens, whatever the circumstances.
In describing emergency contraception's mechanisms of action, the FDA has stated that emergency contraception "works like other birth control pills to prevent pregnancy." The World Health Organization states unambiguously in its guidelines that "[emergency contraceptive pills] are not effective once the process of implantation has begun, and will not cause abortion." Similarly, the American Medical Association, the American College of Obstetricians and Gynecologists, the International Federation of Gynecology and Obstetrics, and a host of other medical institutions have unequivocally stated that emergency contraception does not terminate an established pregnancy.
Women given emergency contraception in advance were no more likely to have unprotected sex, to contract STIs, or to change their use of other contraceptive methods.
Although 16 of 34 (47%) Web sites noted that minors need a prescription for emergency contraception, they failed to mention that in many states, minors can obtain those prescriptions directly from authorized pharmacists.
* 9 states allow pharmacists to dispense emergency contraception without a physician's prescription under certain conditions.
The 100% of the female and 98% of the male respondents reported that they have heard of emergency contraception before.
THIS STUDY was very well conducted and provides genuine insight into adolescents who access contraception and their views about the difference between emergency contraception and nonemergent contraception.
So if you find yourself needing to access emergency contraception, it's good to know your rights ahead of your flight...
The last thing you need on holiday is the stress of trying to locate emergency contraception. Be safe, plan ahead

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