Emergency contraception (EC) is the medical term for methods of birth control that are used immediately after unprotected sex. The most common type of EC involves taking pills that have the same ingredients as birth control pills.

Emergency contraception is not medical abortion, which is defined as using medications instead of surgery to interrupt a pregnancy. EC prevents a pregnancy from starting in a risky situation, i.e., when unprotected intercourse has occurred in mid cycle (the second and third week of the menstrual cycle).

One of the continuing mysteries of EC is how little it has been used, especially given that it is very safe and convenient. Perhaps EC has been pushed off the health radar screen by the sometimes confusing and bitter public discussion of abortion, contraception and their role in women's lives today? This is unfortunate not only because EC is a safe and effective method of contraception but also because widespread use of EC has the potential to reduce drastically the number of abortions performed in the U.S., perhaps the only common goal of most pro-life and pro-choice groups.

The History
Known to medicine since the 1970s, EC uses the same ingredients, synthetic hormones, as conventional birth control pills. Nevertheless it was not until 1997 that the U.S. Federal Register saw fit to publish the doses of the two principal types of EC formulations. These are known as the Yuzpe regimen, which combines estrogen and progesterone, and the progestin-only regimen. At that time in the U.S., women using EC had to find a doctor willing to prescribe and "mix and match" existing contraceptive pills. Now there are two products, Preven® and Plan B® , which are designed specifically for EC.

Acceptance of EC has been steady but slow. Surveys conducted in 1994 and 1995 showed that EC was not well known by consumers in the United States and was rarely prescribed by doctors. Even among obstetrician-gynecologists (OBGYNs), who had a high degree of knowledge about EC (99%) and a willingness to prescribe it, one survey indicated that a majority (75%) prescribed EC fewer than five times a year.

Among women who might have need for EC, survey data showed that only 1% had ever used the technique, even though over one half of women at risk indicated they were interested in trying it. Fully two-thirds of the women surveyed did not know that anything could be done on an emergency basis to reduce the risk of an unplanned pregnancy.

In the years since, however, some promising trends have emerged. The Kaiser Family Foundation's Third National Survey found a doubling of physicians prescribing more than six EC prescriptions per year (OBGYNs 16% to 31%, family physicians (FPs) 8% to 17% from 1995 to 2000). The Kaiser survey also documented that doctors noted a tripling of interest in EC on the part of consumers (OBGYNs 11% to 29%, FPs 6% to 17% from 1997 to 2000).

The Anti-Abortion Pill
EC has tremendous potential for reducing the number of induced abortions in the United States and may in fact already be doing so. From data collected in their 2000 — 2001 survey of women receiving abortions, the Alan Guttmacher Institute estimated that 51,000 fewer abortions were performed in the United States in 2000 because of the use of emergency contraception. It has been estimated that half of the over 5 million pregnancies per year in the United States are unintended, and that half of these end in abortion (approx. 1,300,000 in the year 2000). There is no reason to think that widespread EC could not further reduce this number.

What Exactly Is EC?
There are two medically accepted methods of emergency contraception. The hormonal method consists of various formulations of the synthetic hormones estrogen and progestins, or progestins alone; the other is the emergency insertion of a copper-containing IUD (intrauterine device). The IUD can be used up to five days after unprotected sex and is highly effective. It has the added advantage of continuing to work as a contraceptive for up to ten years. Its use is limited by the fact that special training is needed for insertion, the high initial cost and the fact that some women are not candidates for the IUD for health reasons.

The Yuzpe Regimen
In the mid 1970s, Dr. Albert Yuzpe of Canada began publishing his research on a combination of an estrogen, ethinyl estradiol and a progestin called dl-norgestrel. This medication is administered in two doses taken 12 hours apart, starting within 72 hours after unprotected sex. A number of studies have shown that this reduces the risk of pregnancy by 75%. This means that of the expected eight pregnancies that would occur in 100 women after a single act of unprotected sex in mid cycle (second or third week), six would be prevented. The Yuzpe regimen consisted of 100 mcg of ethinyl estradiol and 1 mg of norgestrel in each of the two doses. One dose is taken immediately and one 12 hours later. The Preven® formulation is equivalent to the Yuzpe regimen but it contains levonorgestrel, which has twice the potency of norgestrel, so only half the milligrams, or 0.5 mg per dose, is needed.

The Progestin-only Method
A high dose of a progestin compound only is also effective. Levonorgestrel (LNG), in a dose of 0.75 mg, given in two doses 12 hours apart, within 72 hours after unprotected sex, has been shown to be equivalent to the Yuzpe method. Plan B® is the progestin-only formulation now on the market.

How Does Hormonal EC Work?
Hormonal EC is thought to work in several ways: by delaying the release of the egg (ovulation), its passage down the fallopian tubes to the uterus, or the readiness of the uterine lining to allow implantation of the fertilized egg (endometrial receptiveness). It is not just a "morning after" pill. There is a well-documented 72-hour window for effectiveness of this regimen, although it does become less effective the later it is taken within that window.

EC certainly should NOT be used as a substitute for regular contraception. Reducing the risk of pregnancy by 75% for one act of intercourse in one cycle does not compare with an effectiveness rate of over 99% for a year, as is seen with oral contraceptives when they are used correctly.There are also significant side effects to taking these hormones in high doses, such as nausea and vomiting, particularly with the Yuzpe method. These are sufficiently unpleasant that few women would want to use it frequently.

Brands and Doses
With the introduction of Preven® and Plan B®, EC has become much more accessible. Until they came along, a doctor wishing to prescribe EC had to cobble together pills from oral contraceptive packages.

Preven® was the first EC product to be released in the U.S.. It is made and marketed by Gynetics, a small private company. It was released in September 1998. It got a big boost in publicity and sales in May of 1999 when Wal-Mart refused to stock it.

Preven® was initially sold as part of a kit containing the medication and a pregnancy test. Later, another version with the pills only became available. The packet contains four blue pills, each containing 50 mcg of ethinyl estradiol and 0.25 mg of levonorgestrel. A dose is two tablets. So for Preven®, a woman takes two tablets as soon as possible after unprotected sex and two more tablets 12 hours later. Preven® has a long shelf life, 48 months.

There are many currently available oral contraceptives that will yield a dosage equivalent to the Yuzpe regimen.

Plan B®
Retail distribution of Plan B® began in September 2000. Like Preven® , it is made and distributed by a small private company, Women's Capital Corporation. The preparation consists of two tablets of levonorgestrel 0.75 mg. One tablet is taken immediately and another twelve hours later. The shelf life is 36 months. One interesting new research finding about the levonorgestrel regimen is that taking both pills at once seems to be as effective as taking them 12 hours apart but this is not the current recommendation of the FDA.

Timing of EC
It is very important to start EC as early as possible in the 72-hour window after sex. It is also important that the second dose be taken exactly 12 hours later. However, you have to be practical. If you take your first dose at 3 PM, you would have to wake up at 3 AM to take the second dose. It might be better for you to take the first dose at 6 PM and the second at 6 AM.

The Yuzpe Versus Progestin-only Regimens
Efficacy: A large trial study published in 1998 definitively showed that the progestin-only regimen was more effective than the Yuzpe. When used correctly, the progestin prevented 89% and Yuzpe prevented 76% of expected pregnancies. Both showed decreasing effectiveness the longer the delay after unprotected sex.

Side effects and contraindications: The package inserts mention all warnings that apply to oral contraceptives, but the incidence of any serious effect is so very low that the World Health Organization (WHO) lists only current pregnancy as a contraindication. The presence of ethinyl estradiol in the Yuzpe regimen is responsible for an increased incidence of nausea and vomiting. Undiagnosed genital bleeding is considered a contraindication for the progestin-only regimen. For both regimens, hypersensitivity to any component or current pregnancy are absolute contraindications, though there is no documented harmful effect on a fetus from either regimen. [Although frequently confused with the "abortion pill," mifepristone, or RU486, these emergency contraceptives, as with the standard oral contraceptives, will not interrupt (or harm) a current pregnancy.]

What to do about nausea and vomiting: These symptoms have been noted with both regimens but are more common with the Yuzpe. The 1998 trial reported nausea 50.5% and vomiting 23% with Yuzpe compared to 18.8% (nausea) and 5.6% (vomiting) with progestin. The main concern is whether the vomiting interferes with the absorption of the medication.

Women who have experienced these side-effects with oral contraceptives are likely to be more susceptible. Although this is something a woman should obviously discuss with her doctor, the current opinion is that if the patient vomits within one hour of pill ingestion or notes the pill(s) in the vomitus, that dose should be repeated, preceded 1 hour by an antiemetic like meclizine (Bonine®) 25-50 mg. Highly susceptible patients may be prescribed an antiemetic as a precaution. As you can see from the statistics, 75% of Yuzpe patients and over 90% of progestin patients will not vomit. Of those that do, most will probably not vomit the entire medication or enough to interfere with its effectiveness. It should be noted that anti-emetics cause drowsiness and anyone taking them should avoid driving or operating heavy machinery.

Resumption of menses, other side effects: Other temporary side effects, such as headache, breast tenderness, dizziness, fatigue and fluid retention may occur. Bleeding or spotting in the 5-7 days after the EC regimen occurs in 10-20% of patients. In the 1998 study, 72% of patients resumed menses early or within three days of their expected date. Fifteen percent experienced a 3-7 day delay and 13% resumed menstruation more than seven days after expected. If menses have not resumed 21 days after the administration of emergency contraception, a pregnancy test should be done. If the woman is found to be pregnant, there is no reason to worry about an adverse effect on the fetus from taking EC. Birth control pills have never been shown to have adverse effects on the fetus, and the FDA required manufacturers to remove warnings about increased risk to the fetus several years ago.

Ectopic pregnancy: When a fertilized egg implants outside the uterus, for example, in the fallopian tube, it is called an ectopic pregnancy, a very dangerous medical situation. There is no evidence that ectopic pregnancy is more frequent in women receiving EC, although this is something that doctors should always be on the lookout for.

A Few Cautions
After taking EC, women should avoid unprotected sex until their menses occur. This is because if EC delayed ovulation, ovulation may yet occur for that cycle. They should abstain from sex or use reliable back-up contraception until their next menstrual period.

When to Get a Pregnancy Test
As mentioned previously, some cycle disruption can occur after EC, making the subsequent menstrual period either a few days early or a few days late. If menses have not started within three weeks after EC, a woman should see her doctor for an exam and a pregnancy test.

Following Up EC
A follow up visit after successful EC is always a good idea. It presents an opportunity to review contraceptive needs with your doctor and to begin or maintain an effective contraception regimen if desired. It is also a chance to discuss protection against STIs (sexually transmitted infectons). As discussed above, although EC is not a good method of regular contraception, it can be repeated without risk. Filling a prescription in advance and keeping it at home is a wise precaution that can mean more immediate use and a higher success rate. Remember, both products have a long shelf life: Preven®, four years, and Plan B®, three years.

Practical Considerations
EC is not used nearly as frequently as it would be if it were more available. The best possible scenario is for women to have the medication on hand and use it if needed. The current products have a shelf life of 3-4 years. The next best scenario is to have the products available at the local pharmacy. Currently, not all pharmacies stock EC pills. To locate pharmacies stocking the medications, consult Plan B, which has a database of pharmacies.

Many doctors are quite willing and able to prescribe EC. If, however, you are "caught out," you can call toll free 1-888-not-2-late and locate a doctor who will prescribe EC. The website Not-2-Late has a searchable database of doctors and facilities able to prescribe EC. In two states, Washington and California, women can get EC directly from their pharmacist. Other states are considering similar bills, including New York. Consult Not-2-Late for updates.

Helpful Websites on Emergency Contraception
Not-2-Late (ec.princeton.edu): This site is operated by the Association of Reproductive Health Professionals and the Office of Population Research, Princeton, University. Searchable database for providers of EC.

Hotline: 1-888-NOT-2-LATE

Preven® (http://www.preven.com): Drug insert, patient information

Plan B® (http://www.go2planB.com): Drug insert, patient protocol and informed consent. Searchable database of pharmacies carrying EC's.

Association of Reproductive Health Professionals (http://www.arhp.org): Good patient care protocol, list of oral contraceptive doses for EC.

Mifepristone, Mifeprex®, RU486, the "Abortion Pill" and EC
Finally, a brief note about the anti-progesterone mifepristone and emergency contraception. Mifepristone, widely known as the "abortion pill," is used with other medications to end a pregnancy by making the hormone progesterone unavailable to sustain the pregnancy. Mifepristone can also prevent pregnancy and is a very effective emergency contraceptive. It works in a way similar to currently available hormonal EC, by postponing ovulation or by delaying maturation of the endometrium, the lining of the uterus where a fertilized egg can implant.

Mifepristone is currently available in the U.S. only for medical abortions. Its availability is restricted to practices and health facilities doing medical abortions under strict protocols, so off label use for emergency contraception would be difficult. Furthermore, studies have shown that only 1/60 of the dose used for abortion, 10 mg vs. 600 mg, is needed for emergency contraception. No such preparation is available in the U.S., although mifepristone is being used for emergency contraception in other parts of the world.

Based on several large studies that have been done on mifepristone as an emergency contraceptive outside the U.S., we know that mifepristone is more effective than the Yuzpe regimen and about equally effective as the progestin-only regimen. There are very few side effects with mifepristone. Vomiting incidence was 1%, the same as the progestin-only in one large study. The dose of mifepristone needed for EC is very low. Ten milligrams was just as effective as the 600 mg used for medical abortions and only a single dose of mifepristone is needed. Because of a strong effect on delaying ovulation, there can be more of a delay in the next menstrual period than with other EC regimens.