Current Issues in Emergency Contraception: An Overview for Providers

Jennifer Brunton, CNM, MSN; Margaret W. Beal, CNM, PhD


J Midwifery Womens Health. 2006;51(6):457-463. 

In This Article

Clinical Management

Safety and Contraindications

The safety of ECPs has been well documented. According to the World Health Organization, the only women who should not use ECPs are those who are already pregnant. This recommendation is given only because the pills would be ineffective if a woman were already pregnant. Studies of women who inadvertently continued to take combined oral contraceptives while pregnant have found no increased risk of having a child with a birth defect, even if the woman took high dose contraceptive pills.[22]

The American College of Obstetricians and Gynecologists suggests three contraindications to ECP use: known or suspected pregnancy, hypersensitivity to any ingredient in the product, or undiagnosed abnormal genital bleeding. Use of ECPs is not contraindicated in those women who have contraindications to daily use of oral contraceptives, because the exposure to hormones in ECPs is for a very short duration, and has not been shown to be associated with the same adverse effects as continued oral contraceptive use. However, in women with absolute contraindications to combined pills, such as migraine with neurologic symptoms or a history of stroke or blood clots, the use of progestin-only ECPs or a copper IUD may be preferred.[22]

Although cases of ectopic pregnancy have been reported with both the Yuzpe regimen as well as with Plan B, there is no increased risk of ectopic pregnancy with the use of ECPs. In fact, the rate of ectopic pregnancy may even be lower among EC users than in the general population because of the number of pregnancies that are prevented.[23]

Normal contraindications to IUD insertion applies when considering the copper IUD for emergency contrapception.[6,23]

Implementation: Timing and Efficacy

The efficacy of any EC method is difficult to measure and depends on several factors, including the length of a woman's menstrual cycle, cycle day of unprotected intercourse, and the time within which ECP was taken after intercourse.

The levonorgestrel- and norgestrel-containing progestin-only EC methods have proven more effective than combined ECPs, reducing the risk of pregnancy by about 89%, to only 1 pregnancy per 100 women.[6] Although published evidence is lacking, many clinicians prefer the progestin-only method, believing that the lower incidence of nausea and vomiting contributes to the higher efficacy.

The Yuzpe regimen reduces the risk of pregnancy by 75%, from roughly 8 pregnancies per 100 women without treatment to about 2 per 100 women after combined ECP use. One large trial conducted by the World Health Organization showed a significant decline in effectiveness as delay to administration of treatment increased. Although effectiveness is somewhat decreased after 72 hours, ECPs are still effective after this time, and should be offered up to 120 hours (5 days) after unprotected intercourse. The highest rates of effectiveness occur when the Yuzpe regimen is started within 24 hours of unprotected intercourse.[1,6,24,25]

Although it is not used much in the United States, the copper IUD T 380A is another effective form of EC. The most recent prospective study of the efficacy of the copper IUD followed 1013 women in China, using the Multiload Cu-375, an IUD produced by Organon (Roseland, NJ) and marketed in China.[16] This IUD is used in many countries around the world and is equivalent to the T380A used in the United States under the name ParaGard (FEI Products, North Tonawanda, NY).[26] Women were eligible for the IUD if they presented within 120 hours of unprotected intercourse and had a negative urine pregnancy test. Efficacy in pregnancy prevention was higher (98%) in parous women than in nulliparous women (92.4%), but lower than that previously reported in a meta-analysis conducted by Trussell and Ellertson,[27] which found an efficacy of 99%.

Use of the Cu IUD for postcoital contraception is managed similarly to the oral forms of EC, in that the method can be used up to 120 hours after intercourse, and women are instructed to return for care if their menses do not return after 3 weeks.[6]

Resuming or Starting a Contraceptive Method

Provision of EC should include assessment of the need for ongoing contraception. If the reason for using EC was because of missed OCPs, the woman may resume taking her oral contraceptives the day after EC use, and should be advised to use a back up method, such as condoms, for the first 7 days. Similarly, women initiating hormonal contraceptives, such as pills, patch, or a vaginal ring, may begin the day after EC use, with use of a backup method for 7 days. Alternatively, the method may be started with the next menses.[6]

Providers should warn women that taking ECPs may affect their next menstrual period, which may be later or earlier and/or of a longer duration than usual.[28] Women are advised to see their provider for a pregnancy test if menses have not returned within 3 weeks.[29] There are no additional considerations regarding the copper IUD when it is initiated for EC.[6]

Side Effects

The most common side effects when using hormonal EC are nausea and vomiting, with progestin-only pills having a much lower incidence of these side effects than combined hormone preparations. Recent studies by the World Health Organization have shown low rates of these side effects after progestin-only EC use, making antiemetic administration unnecessary.[30] The reduced incidence in vomiting associated with progestin-only pills is particularly desirable because vomiting within 2 hours of administration can decrease absorption of the drug and adversely affect its efficacy.

The incidence of nausea after administration of combined hormonal pills (as in the Yuzpe regimen) was reported in a 1998 study to be 50.5%, with 18.8% of women experiencing vomiting. Because of this, antiemetics should be recommended for women using combined hormone methods of EC. Two 25 mg tablets of meclizine hydrochloride (over-the-counter Dramamine or Bonine [both from Pfizer, Inc., New York, NY]) can be taken 1 hour before use to prevent nausea and vomiting.[6,9,16]

Other side effects include dizziness, fatigue, headache, breast tenderness, and lower abdominal pain, each of which had a lower incidence after administration of levonorgestrel-only versus combined hormonal contraceptive pills as EC. Both combined and progestin-only pills can also have an effect on menstruation. Although the changes are usually minor, emergency contraceptive pills can cause spotting and can affect the timing, duration, and flow of the next menstrual period.[30]

Side effects of copper IUD insertion for EC are the same as those expected with any insertion, including vaginal bleeding or spotting and abdominal cramping.[6]


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