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Physicians have known for three decades that taking high doses of oral contraceptive pills afterunprotected intercourse can prevent ovulation and implantation. Isn't it time you considered offering adolescent patients this effective means of avoiding unintended pregnancy?
|Jump to:||Choose article section...HistoryMechanism and efficacyIndicationsContraindicationsThe Yuzpe regimenThe wave of the future: Progestin-only regimensKnowledge and accessHow and when: A step-by-step guideGiving teens a second chance|
By Melanie A. Gold, DO
Physicians have known for three decades that taking highdoses of oral contraceptive pills afterunprotected intercourse can preventovulation and implantation. Isn't it time you considered offering adolescentpatients this effective means of avoiding unintended pregnancy?
Emergency contraception, previously called the morning-after-pill orpostcoital contraception, is a means of preventing pregnancy after unprotectedintercourse. The term "morning-after-pill" has fallen out of favorbecause it misstates the time frame; in fact, most methods of emergencycontraception are effective for up to 72 hours after intercourse, and somedata suggest the risk of pregnancy can be reduced for up to 120 hours postcoitus.1
Emergency contraception is not new. High-dose estrogens were first usedto prevent pregnancy after rape in 1969.2 However, severe nauseaand vomiting limited their use.3,4 In 1974, a Canadian obstetrician-gynecologistnamed Albert Yuzpe developed an emergency contraceptive regimen combiningestrogens and progestins that allowed a reduction in the total dosage ofestrogens.5 This new combination, called the Yuzpe regimen, hadfewer side effects and was better tolerated without sacrificing significantefficacy.6 Today the Yuzpe regimen is the most common methodof emergency contraception used in the United States. The first prepackagedformulation of the Yuzpe regimen, Preven, was approved by the Food and DrugAdministration (FDA) on September 2, 1998.
Nonhormonal emergency contraception goes back to 1976, when a copperintrauterine device (IUD) was inserted for the first time as an emergencycontraceptive method.7 Postcoital IUD insertion is highly effective,with a failure rate of 0.1%. However, its use is very limited in the US,especially for nulliparous or very young women, because of concerns aboutperforating the uterus or increasing the risk of pelvic inflammatory disease.
In the 1990s, high-dose progestin-only pills containing levonorgestrelwere also found to be effective for emergency contraception.810At this time, however, no high-dose levonorgestrel preparations areavailable in the United States. Danazol, an anti-gonadotropin,was initiallyinvestigated as an emergency contraceptive but was found to be ineffectivein a controlled trial comparing it with the Yuzpe regimen and is no longerrecommended.11 Mifepristone (also called RU486), a progesteronereceptor antagonist, is an excellent emergency contraceptive. It has fewerside effects of nausea and vomiting than estrogen-based methods and no failureswith this method have been reported.11,12 Because mifeprestoneis entangled in controversy over its use for first trimester abortion, itprobably will not be readily available for use as an emergency contraceptivefor a number of years. Currently high-dose combination oral contraceptivepills and high-dose progestin-only pills are the primary forms of emergencycontraception used in the US.
Emergency contraceptive pills prevent pregnancy in two ways. First, theyalter the endometrial lining to prevent implantation.13 Second,depending on when in the ovulatory cycle they are taken, emergency contraceptivepills may inhibit the luteinizing hormone (LH) surge and thereby preventovulation.14,15 Other mechanisms such as thickening cervicalmucus to impair sperm motility and altering tubal transport are thoughtto play a lesser role.
The risk of pregnancy amongwomen taking the Yuzpe regimen within 72 hoursof unprotectedintercourse is reduced by 70% to 80%.16,17 Theefficacy of emergency contraception is measured against the likelihood ofpregnancy for a single episode of unprotected intercourse during a particulartime in the menstrual cycle. If the risk of pregnancy after unprotectedintercourse is 32% on the day before ovulation, for example, the Yuzpe regimencan reduce the risk to 8%.
Risk is difficult to estimate for adolescents, since they often haveirregular menstrual periods, do not ovulate with every cycle for severalyears postmenarche, and frequently are unsure of the date of their lastmenstrual period. For that reason, the timing of menses should not be usedto determine the need for emergency contraception. Instead, emergency contraceptionshould be offered at any time unprotected intercourse has occurred. Recentstudies indicate that the high-dose levonorgestrel regimen is more effectivethan the Yuzpe regimen. Further, the efficacy of either regimen can be improvedif the medication is used as soon as possible after unprotected intercourse,or at least within 24 hours.10
Until fairly recently, the use of emergency contraception was largelylimited to the emergency room, where it was sometimes prescribed for womenwho had been raped. But with the current emphasis on preventing unintentionalpregnancy, especially among adolescents, the indications are beginning tobe viewed more broadly. Some physicians have now come around to the viewthat any situation in which a woman has had unprotected intercourse andwishes to prevent pregnancy is an indication for emergency contraception.Possible scenarios include:
Some physicians recommend offering emergency contraception if unprotectedintercourse occurs after a single oral contraceptive tablet is missed atthe end of the third week of taking hormonally active pills, or at the beginningof a new pill pack, when the hormone-free period is longer than seven days.18
Contraindications are not the same as those for combination hormonalpills used for ongoing contraception. The only contraindication for theYuzpe or levonorgestrel regimen is pregnancy, because the regimens are noteffective once a fertilized egg has implanted into the endometrial lining.However, if emergency contraceptive pills are taken accidentally duringpregnancy, they will not cause an abortion, a miscarriage, or any teratogenicanomalies.1921 In the United Kingdom, concurrent migrainewith focal neurologic deficit is also considered to be a contraindication.
A history of a deep vein thrombosis, pulmonary embolism, stroke, or heartattack is a relative contraindication for estrogen-based regimens, but theseconditions are exceedingly rare among adolescent women. Health-care providerswho are uncomfortable providing estrogen-based emergency contraception toan adolescent with a past history of thromboembolic or cardiovascular eventscan consider other postcoital options such as high-dose progestins or postcoitalIUD insertion.
A history of ectopic pregnancy is not a contraindication but does indicatea need for careful follow-up since a woman with such a history is at riskfor a repeat ectopic pregnancy if the emergency contraceptive method shouldfail. For these patients, a confirmatory pregnancy test should be performedtwo to three weeks after the emergency contraceptive pills are taken. Ifthe pregnancy test is positive, a determination of the site of implantationmust be made.
The Yuzpe regimen requires 200 mcg ethinyl estradiol plus either 2.0mg norgestrel or 1.0 mg levonorgestrel divided into two separate doses,given 12 hours apart. Any combination of pills on the market can be usedif they meet these requirements. When lower dose pills are used, it maybe necessary to exceed the estrogen dose in order to meet the minimum progestindosage. The FDA affirmed the safety and efficacy of certain combined oralcontraceptive pills for emergency contraception and published specific protocolsfor their use in February, 1997.22 Eleven combination oral contraceptivepills available on the US market can be used for the Yuzpe regimen; dosagesare given in the table.
The only product specifically packaged for emergency contraception useis Preven (Figure 1). The Preven Emergency Contraception Kit contains aurine pregnancy test, an information guide, and four blue tablets, eachcontaining 50 mcg of ethinyl estradiol and 0.25 mg of levonorgestrel. Pricedat $20, the Preven kit is cheaper than most packs of combination oral contraceptivepills used for the Yuzpe regimen. Health insurance that covers other formsof hormonal contraception will usually cover Preven, and the Health CareFinancing Administration has approved Preven for Medicaid reimbursement.
The most common side effects of the Yuzpe regimen are nausea (occurringin 30% to 50% of users) and vomiting (15% to 20%). Other side effects includebreast tenderness, abdominal cramping, menstrual irregularity, fatigue,dizziness, headache, and mood changes.
In 1998, the Task Force on Postovulatory Methods of Fertility Regulationreported the findings of a randomized controlled trial of levonorgestrelversus the Yuzpe regimen.10 The investigators found that womenusing levonorgestrel were significantly less likely to have nausea (23%vs. 51%), vomiting (6% vs. 19%), dizziness (11% vs. 17%) and fatigue (17%vs. 29%) than those using the Yuzpe regimen (all P<0.01). More important,pregnancy rates were significantly lower in the levonorgestrel group (1.1%)than in the Yuzpe group (3.2%). The percentage of pregnancies prevented(on the basis of the estimated likelihood of conception following unprotectedintercourse during a particular time in the menstrual cycle) was 86% inthe levonorgestrel group, compared to 58% for the Yuzpe group.10,23When levonorgestrel was used within 24 hours of unprotected intercourse,95% of pregnancies were prevented as compared with only 77% among womenwho used the Yuzpe regimen in the same time frame.
The problem with the progestin-only regimen is that a suitable dosageform is not currently available in this country. The regimen requires atotal of 3 mg of norgestrel (or 1.5 mg of levonorgestrel) in two doses taken12 hours apart. The only progestin tablet now available in the US is Ovrette,a very low-dose pill that contains only 0.075 mg of norgestrel per tablet.With that formulation, a patient needs to take 20 tablets for the firstemergency contraception dose and another 20 tablets 12 hours later. Theprospect of swallowing 40 tablets within 12 hours is daunting. In addition,the progestin-only pills are more expensive than the combination OCs usedfor the Yuzpe regimen. Two packages of Ovrette needed to complete the regimencost approximately $70. The FDA is currently reviewing an application fora high-dose tablet with enough progestin to complete the emergency regimenwith two pills. When it is approved, it will probably replace the Yuzperegimen as the standard treatment.
Emergency contraception, as we've seen, is safe, effective, and FDA-approved.But it won't protect adolescent patients from unintended pregnancies unlessthey know it's an option and can get timely access to it. Unfortunately,most teenage girls in the US (66%) do not even know that emergency contraceptionis possible.24,25
Pediatricians can do a great deal to remedy this situation. They caninclude information about emergency contraception in routine counselingduring all adolescent visits, as well as during visits devoted specificallyto contraceptive counseling. Both male and female adolescents should betaught about emergency contraception since both have a responsibility toprevent unintended pregnancy.
Anticipatory guidance should not be limited to teens who are alreadysexually active. Indeed, since adolescents often fail to use contraceptionat their first intercourse, sexually inexperienced teens are particularlyin need of this information. There is no reason to suppose that learningabout emergency contraception will encourage adolescents to initiate sexualactivity; rather, like other kinds of sex education, such knowledge is likelyto promote safer sexual behavior in those who have already decided to besexually active. Information about emergency contraception should also beavailable in the office on posters, wallet cards that teen patients canpick up discreetly in the waiting room or bathroom, and guides (like the"Guide For Patients") that they can take home or share with friends.For information on where these materials can be obtained, see "Resourcesfor physicians and teens".
Requests for emergency contraception can lead to visits for contraceptiveeducation and identify patients who should be receiving routine gynecologiccare and screening for sexually transmitted diseases. In addition, counselingadolescents about emergency contraception lets them know that their pediatricianis willing to provide reproductive health-care services.
Knowledge is the sine qua non, but effective use of emergency contraceptionalso requires timely access. One way to accomplish that is to provide emergencycontraceptive pills in advance. This can be done by writing a prescriptionfor patients to have on hand in case an episode of unprotected intercourseoccurs. Oral contraceptive pills have a shelf-life of approximately oneand a half to two years and should be stored at room temperature. Patientsshould check the expiration date on the package before using the pills.
The fear that women who have pills on hand for emergency use will abandonroutine contraceptive measures is not warranted.26 GlasierandBaird have shown that although women who are provided with emergency contraceptionin advance are more likely to use it (47%) than women who have to call fora prescription (27%), they are not more likely to use it repeatedly.27Nor were there any differences between the women who had emergency pillson hand and the others in the way they used other methods of contraception.
Because emergency contraception has only recently become widely knownand easily available, you will probably need some guidance on how to incorporateit into your practice. The first step is to ask each female adolescent whocomes into the office if she is sexually active or plans to be in the nearfuture. Counsel patients who are not sexually active about abstinence andotheravailable forms of contraception. Include a description of emergencycontraception and offer a prescription for Preven if the patient says shewould like to have an emergency contraceptive kit at home.
If the adolescent is already sexually active, inquire when she had herlast menses, when she last had intercourse, and what method of contraceptionwas used. If she has had unprotected intercourse within the last 72 hours,do a urine HCG test to rule out current pregnancy from prior episodes ofunprotected intercourse (Figure 2). Ask if she wishes to avoid pregnancy;review what emergency contraception is, how it works, the efficacy and failurerate, and side effects; and offer to write a prescription. If a patientwho needs emergency contraception can't get to the office within three days,you can prescribe over the telephone. Ask to see the patient in two weeks,so that a pregnancy test can be done to make sure the pills worked, andtell her not to have sex in the interim.
At the visit when you dispense emergency contraception, and again atthe follow-up visit, discuss contraceptive plans for the future. Reviewoptions including abstinence, oral contraceptive pills, Depo- Provera, andcondoms (either alone or with a vaginal spermicide). If a patient choosesoral contraceptives, she can begin a new package of pills the day aftertaking the second dose of the emergency contraception or she can wait tostart on the first day of her next period. If she fails to get a menstrualperiod by the time of the follow-up appointment, then the pills can be startedthe day of the visit as long as she has a negative urine pregnancy testand has been abstinent since taking the emergency contraception. If thepatient had been taking oral contraceptive pills but misses two or moretablets, instruct her to start a new package of pills the day after shetakes the emergency contraceptive pills. Remind her to follow up in twoweeks for a repeat pregnancy test. If she chooses depot medroxyprogesteroneacetate injections (Depo-Provera), you can give the first injection withinfive days of the next menstrual period or at the follow-up appointment aslong as the urine pregnancy test is negative and she has been abstinentsince taking the emergency contraceptive pills.
At the follow-up visit, consider doing a pelvic exam to rule out exposureto sexually transmitted infection. Include testing for gonorrhea and Chlamydiaand a wet mount for Trichomonas. A pelvic examination is not necessary beforeprescribing emergency contraception unless a patient has symptoms of a sexuallytransmitted infection. Symptoms that indicate the need for a pelvic examinationinclude urinary frequency, urgency, or dysuria, intermenstrual or postcoitalvaginal bleeding, dyspareunia or pain on intercourse, pelvic pain, vaginalitching, or the presence of any unusual vaginal discharge or odor. Futurecontraceptive plans should be revisited after the pregnancy scare has beenresolved. You will find answers to some of the questions teens are mostlikely to ask about emergency contraception.
Emergency contraception offers adolescent women who have had intercoursewithout protection a second chance to avoid an unintended pregnancy. Makingemergency contraception easily available is not harmful, does not discourageother contraceptive use, and may prevent physical, psychological, andmedicalcosts associated with unintended pregnancy.28 That's an opportunityprevention-minded pediatricians probably won't want to pass up.
Acknowledgments: Special thanks to Robin Madden, MD, Joshua Madden, MD,and David Nash, MD, for their critical review of the manuscript.
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THE AUTHOR is Assistant Professor of Pediatrics, University of PittsburghSchool of Medicine, Pittsburgh, PA.
She has a research grant from Pharmacia-Upjohn, the makers of Depo-Provera.