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Emergency contraception (EC) (also known as Emergency Birth Control (EBC), the morning-after pill, or postcoital contraception) refers to measures, that if taken after sex, may prevent a pregnancy. Forms of EC include: As opposed to regular methods of contraception, ECs are considered for use in occasional cases only, for example in the event of contraceptive failure. Since they act before implantation, they are considered medically and legally to be forms of contraception. Some pro-life groups define pregnancy as beginning with fertilisation, and therefore consider EC to be an abortifacient. These claims remain controversial; see below. ECPs Emergency contraceptive pills (ECPs), are an oral drug containing high doses of the same hormones found in regular oral contraceptive pills, which, when taken after unprotected sexual intercourse, may prevent pregnancy from occurring. Studies in rats and monkeys have shown that ECPs have no effect on pregnancy rates when taken after ovulation has already occured.• These changes are similar to those found in a woman's first few ovulatory breastfeeding cycles.• Because these secondary effects might result in embryos being created, but prevented from implanting in the uterus, they have resulted in some controversy over the use of ECPs. The phrase "morning-after pill" is figurative: ECPS are licensed for use up to 72 hours after sexual intercourse, not just the morning after. Emergency contraception or "emergency contraceptive pills" is the phrase preferred by the medical community. Types of ECPs The progestin-only method uses the progestin levonorgestrel in a dose of 1.5 mg, either as two 750 μg doses 12 hours apart, or more recently, as a single dose, and is available as a dedicated emergency contraceptive product in the U.S. and Canada as Plan B, in the UK as Levonelle, and in France as NorLevo. The combined or Yuzpe regimen uses large doses of both estrogen and progestin, taken as two doses at twelve hour intervals. This method is now known to be less effective and less well tolerated (more nausea and vomiting) than the progestin-only method. "Dedicated products" such as Plan B, Levonelle and NorLevo are specifically designed and marketed as emergency contraceptive pills. It is also possible to obtain the same dosage of hormones, and therefore the same effect, by taking a number of regular progestin-only or combined estrogen-progestin oral contraceptive pills.• The drug mifepristone may be used either as an ECP or as an abortifacient, depending on if it is used before or after implantation. In the USA it is most commonly used in 200- or 600-mg doses as an abortifacient,• but in China it is commonly used as an ECP. Used for ECP, a low dose is slightly less effective than higher doses, but has fewer side effects.• As of 2000 the smallest dose available in the USA was 200mg.• A review of studies in humans concluded that the contraceptive effects of the 10-mg dose are due to its effects on ovulation,• but understanding of the mechanism of action remains incomplete. Higher doses of mifepristone can disrupt implantation, and, unlike levonorgestrel, mifepristone is effective in terminating established pregnancies. Effectiveness of ECPs The effectiveness of emergency contraception is calculated differently than that of ongoing birth control methods. For ongoing methods, the effectiveness rate is defined as the number of pregnancies over one year of use. For EC, the effectiveness rate is defined in clinical trial conditions as the reduction in pregnancy rate from a single use of emergency contraception. Calculating the exact effectiveness of emergency contraceptive pills is difficult because the risk of pregnancy is not a steady percentage--it is extremely high in the several days immediately before ovulation, and negligible the rest of the time. Different measures have been used to estimate the effectiveness of different types of ECPs. These measures include comparing two types of ECPs against each other, or assuming some average expected pregnancy rate such as 8% per act of intercourse. Levonorgestrel ECPs prevent at least 50% of expected pregnancies among women who take them correctly.• A subsequent WHO study has suggested reasonable effectiveness continues for up to 120 hours (5 days),• Because women in EC clinical trials are likely to face higher pregnancy risk than the general population, the estimated number of pregnancies averted by treatment may be overestimated. Variables which can affect EC effectiveness other than the 8% "adjusted day of unprotected intercourse" include regularity of menstrual cycle, recent hormone use, breastfeeding, and the number of acts of unprotected intercourse. • Abortion rates and EC ECPs have not lowered abortion rates. In France, Sweden, and the UK — where EC has been available for more than a decade — the abortion rate is not lower. • A randomized, controlled trial in China found no evidence that readily available ECPs reduced abortion rates.• ECPs as a birth control method Emergency contraception cannot be recommended as the main means of birth control because it is not as effective as any ongoing method of contraception. It also does not protect against sexually transmitted infections. However, it is used by some as a back-up when other means of contraception have failed—for example, if a woman has forgotten to take a birth control pill or when a condom is torn during sex. It is also a first line of treatment option for victims of sexual assault. Contraindications & Interactions Plan B and Yuzpe should not be used by women who are already pregnant because they are not effective then.• The herbal preparation of St John's wort and enzyme-inducing drugs (e.g. anticonvulsants or rifampicin) may reduce the effectiveness of ECP and a larger dose may be required. (Levonorgestrel 1500mcg initial dose and an extra 750mcg after 12 hours) Side effects The most common side effect of emergency contraception pills are nausea, abdominal pain, fatigue, headache, dizziness, vomiting, and breast tenderness. These side effects are normally resolved within 24 hours. The rate of these effects occurring is less for progestin-only pills when compared to combined pills. Also common is temporary disruption of the menstrual cycle, which may manifest as early or late periods, spotting or breakthrough-bleeding, and (less commonly) missed periods. The primary mechanism of EC is delaying ovulation. Menstruation occurs on average 14 days after ovulation, so a delayed ovulation will result in a delayed menstruation. Suppression of ovulation may cause anovulatory bleeding, which could manifest as an early period. Confirmation of Results A pregnancy test is the only reliable way to confirm whether or not EC has been effective. EC can cause menstrual changes that appear similar to early signs of pregnancy, and some doctors therefore advise all women who take EC to take a pregnancy test afterwards to get confirmation of the results. Pregnancy tests will not give positive results until after an embryo has implanted, which occurs six to twelve days after ovulation. The most sensitive tests can detect pregnancy the day after implantation, so the earliest a positive result would be seen would be one week after intercourse (assuming intercourse occurred on the day of ovulation). Sperm life of up to five days is considered normal, and less sensitive tests may not detect pregnancy until three to four days after implantation. So a pregnancy test may give false negatives up to three weeks after intercourse (five days between intercourse and ovulation, twelve days between ovulation and implantation, four days between implantation and detectable levels of the pregnancy hormone hCG). Intrauterine device used for emergency contraception An alternative to emergency contraceptive pills is the copper-T intrauterine device (IUD) which can be used up to 5 days after unprotected intercourse to prevent pregnancy. Insertion of an IUD is more effective than use of Emergency Contraceptive Pills - pregnancy rates when used as emergency contraception are the same as those of normal IUD use. IUDs may then be left in place following the subsequent menstruation to provide ongoing contraception (3-10 years depending upon type).• History Interest in hormones as postcoital contraceptives originated several decades ago, with the first published study on the subject appearing in 1967.• A large number of different drugs were studied, and it was originally hoped that postcoital contraception would prove viable as an ongoing contraceptive method.• The first FDA-approved method (approved in 1973) was a five-day treatment with diethylstilbestrol (DES).• The Yuzpe regimen was developed by AA Yuzpe in 1974.• Progestin-only postcoital contraception was first investigated in 1975.• Also in 1975, the copper IUD was first studied for use as emergency contraception.• The Yuzpe regimen became the preferred course of treatment for women asking for postcoital contraception, and several dedicated products were produced. However, as it became clear that the Yuzpe regimen is less effective and causes more side effects than progestin-only ECPs, dedicated combined estrogen-progestin emergency contraceptive products were withdrawn (Preven in the United States discontinued May 2004, Schering PC4 in the United Kingdom discontinued October 2001, and Tetragynon in France). Related Studies and Statistics Emergency contraception, implantation, and abortion politics A number of studies in the 1970s and 80s concluding that emergency contraception could cause changes in the endometrium, and thus preventing implantation of an early stage embryo in the uterus, led many pro-life advocates, who widely believe that pregnancy begins at fertilisation, to oppose ECPs as an abortifacient. In recent years, however, especially in light of U.S. controversy over this possibility, the scientific community has begun to critically reevaluate the claim, introducing doubt into the argument that ECPs prevent implantation. Recent studies in rats and monkeys have shown that post-ovulatory use of ECPs do not have any effect on pregnancy rates. Studies in humans have shown that the rate of ovulation suppression is approximately equal to the effectiveness of emergency contraceptive pills, suggesting that might be the only mechanism by which they prevent pregnancy. However, these studies have also shown that, in women who ovulate despite taking ECP before ovulation, there are changes in certain hormones such as progesterone and in the length of their luteal phase. These secondary changes might inhibit implantation in cases where fertilization occurs despite ECP use. Because of the difficulty of studying pre-implanted embryos inside the uterus and fallopian tubes, both sides of this debate concede that completely proving or disproving the theory may be impossible. The Food and Drug Administration recently stopped its practice of referring to all three mechanisms in its publications on emergency contraception. However, the approved box design for Plan B, an emergency contraceptive approved for over-the-counter sale in the United States, will still carry a notification that it may prevent implanation. When used as a regular method of contraception, IUDs have been proven to act primarily through spermicidal and ovicidal mechanisms. However, it is theoretically possible that these same mechanisms are also harmful to pre-implanted embryos. Hormonal progestin-only and combined estrogen-progestin emergency contraceptives such as Yuzpe regimen or Plan B are different from the anti-hormonal drug mifepristone (also known as Mifeprex and RU-486), an abortifacient which can induce abortion if taken after implantation. Yuzpe and progestin-only emergency contraception will have no effect if taken after implantation. United States legal and ethical controversies United Kingdom As of early 2001, women of age 16 and older may obtain emergency contraception in the United Kingdom without a prescription. This was challenged by an anti-abortion group, but the High Court of Justice of England and Wales let the rule stand in April 2002. United States Since December 2000, the official policy of the American Medical Association (AMA) has supported Food and Drug Administration (FDA) approval of over-the-counter (OTC) access to emergency contraception without a prescription in the U.S. One year later, after the 2004 Presidential election, the makers of Plan B reapplied for over-the-counter status for women aged 16 and older. The January 2005 deadline for the FDA decision on this application passed without a decision. The FDA pledged to rule on the application by September 1, 2005, but the deadline was extended for at least 60 days. Barr re-filed its application for Plan B for OTC access for those 18 and older. President George W. Bush stated that he would support FDA head Andrew von Eschenbach's decision to approve Barr's application as long as minors did not get the drug without a prescription.. The FDA announced approval on August 24 2006 for emergency contraception sales to those over 18 years of age over-the-counter. Girls aged 17 and under still require a prescription. Plan B will not be available in gas stations or convenience stores as are some other OTC medications, and sales will be limited to locations with a pharmacist on staff. Before this decision, eight states (California, Washington, Alaska, Hawaii, New Mexico, Maine, New Hampshire and Massachusetts) passed laws permitting trained pharmacists to dispense emergency contraception without a doctor's prescription. There is no evidence that direct access to ECPs without a prescription results in fewer unintended pregnancies than controlled access via prescription. • Canada In April, 2005, Canada approved over-the-counter sales of Plan B. • France In January 2000, France decided to dispense emergency contraception in junior and high schools by school nurses without prescription, because of high rates of undesired pregnancies among teenaged girls. After strong opposition from the Roman Catholic Church, and much debate around the fact the teenager could later suffer from the doubt of not knowing whether fertilization had occurred or not, the decision was overruled by a court in July 2000. The French parliament changed the relevant law in October 2000 and now school nurses are again able to dispense the drugs. The emergency contraception pill NorLevo is now available in France without prescription, without parent authorization, and free of charge for teenagers under the age of 18 since January 9, 2002. Other Countries Emergency contraception is available without prescription in the following countries: Albania, Australia, Belgium, Benin, Bulgaria, Cameroon, Canada, Chile, China, Colombia, Congo, Croatia, Denmark, Estonia, Finland, France, French Polynesia, Gabon, Ghana, Greece, Guinea-Conakry, Iceland, India, Israel, Ivory Coast, Jamaica, Latvia, Lithuania, Madagascar, Mali, Mauritania, Mauritius, Morocco, Mexico, Netherlands, New Zealand, Norway, Portugal, Romania, Senegal, South Africa, Sri Lanka, Sweden, Switzerland, Togo, Tunisia, Turkey, the United Kingdom, Italy and Uruguay. In Ireland it is available without restriction, but is not available over-the counter and requires a visit to a doctor of family-planning clinic. Footnotes | |||||||
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