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. However, some who are anti-abortion define pregnancy as beginning with fertilisation, so they consider EC to be a form of abortion. These claims remain controversial; see Controversy section for more detail.
There are several mechanisms of action by which such drugs may work. Depending on the time during the menstrual cycle that they are taken, this drug may inhibit or delay ovulation, inhibit tubal transport of the ovum or sperm cell, or interfere with fertilization. In cases where it fails to prevent fertilization, it may prevent implantation; however, studies into the method of action of progesterone-only ECP have called into question whether ECPs do actually disrupt or prevent implantation. In this respect, emergency contraceptive pills work by triggering the same hormonal changes in the body as regular birth control pills or even breastfeeding — but they require much higher doses and are less effective than ongoing hormonal contraceptives.
The phrase "morning-after pill" is a misnomer that is falling out of use due to the fact they are licensed for use up to 72 hours after sexual intercourse. Emergency contraception or "emergency contraceptive pills" is the phrase preferred by the medical community. Unlike forms of chemical abortion such as Mifepristone, emergency contraception does not end pregnancies and will not harm a developing embryo.
The progesterone-only method uses the progesterone levonorgestrel in a dose of 1.5 mg, either as two 750 μg doses 12 hours apart, or more recently, as a single dose. This method is now known to be more effective (up to 89%) and better tolerated (less nausea or vomiting) than the Yupze method WHO Task Force on Postovulatory Methods of Fertility Regulation. Randomised controlled trial of levonorgestrel versus the Yuzpe regimen of combined oral contraceptives for emergency contraception. Lancet 1998;352:428-433. (Abstract), and is available in the U.S. and Canada as Plan B, in the UK as Levonelle, and in France as NorLevo.
"Dedicated products" such as Plan B and Levonelle 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 normal Progesterone only pills.
ECPs are most effective the sooner they are takenReviewing editorial from the BMJ 2003;326:775-776 ( 12 April ) Editorial. The limit of 72 hours is based on a study by the WHO. A subsequent WHO study has suggested reasonable effectiveness continues for up to 120 hours (5 days)Low dose mifepristone and two regimes of levonorgestrel for emergency contraception: a WHO multicentre randomised trial. Lancet 2002; 360: 1803-1810 PMID 12480356, however many doctors (particularly in the UK) advise alternative methods for between 72 and 120 hours. These are covered below.
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)For women who are using liver enzyme inducing drugs, what dose of progestogen-only emergency contraception is advised? PDF members response 916 Faculty of Family Planning and Reproductive Health Care - Clinical Effectiveness Unit else consider the use of an IUD (see below).
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.
More information on side effects is available in the patient information leaflet associated with the brand of EC in question.
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 occured on the day of ovulation). Normal sperm life is up to five days, and less sensitive tests may not detect pregnancy until three to four days after implantation. So a pregnancy tests 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).
However, in May of 2004 the FDA refused this strong recommendation and prohibited over-the-counter sale. The FDA claimed that this was due to limited experimental data on the effects of such pills on girls under 16 years of age, but critics have accused the FDA of basing the decision on political pressure. Kaufman, Marc. "Plan B Won't Be Sold Over Counter". Washington Post. May 7, 2004; Page A01. Accessed April 28, 2006. One year later, a new application from the makers of Plan B requested over-the-counter status for women aged 16 and older, but the January 2005 deadline for the FDA decision on this application has come and gone without a decision. The FDA had more recently pledged to rule on the application by September 1, 2005, but this deadline has been extended for at least 60 days. However, in the United States, as of March 2006, eight states (California, Washington, Alaska, Hawaii, New Mexico, Maine, New Hampshire and Massachusetts) had passed laws permitting trained pharmacists to dispense emergency contraception without a doctor's prescription. On November 3, 2005, HR 4229 was introduced in the United States House of Representatives, which would require the FDA to make a decision on Plan B.
In a number of instances across the United States, pharmacists have refused to give women emergency contraception even with a legal prescription. These pharmacist refusals have created great controversy. Pro-life pharmacists who believe that emergency contraception is equivalent to abortion, or who, for personal moral or religious reasons oppose the use of birth control pills for unmarried women, or at all, have in a number of instances across the United States asserted a right of conscience to refuse to fill those prescriptions. The American Pharmacists Association has proposed conscience clauses or refusal clauses that would allow pharmacists to opt out of filling prescriptions they found morally offensive as long as they referred women to other pharmacists who would fill the prescription.
Women's rights and pro-choice organizations have expressed concern that in many parts of the country there may not be reasonably accessible alternatives to fill a prescription; and that having a prescription refused is intimidating and upsetting to women who are likely to be in a crisis situation. As well, in the instance of emergency contraception, there is a short window of time during which EC is effective. Advocates for women say that conscience clauses are often overly broad, and that women have a right to medically appropriate, effective, and legal reproductive health services without being refused such services because of the medical professional's personal beliefs.
Emergency contraception pills are birth control pills, containing the same ingredients as birth control pills, but at a higher dosage. Like birth control pills, emergency contraception pills work by preventing ovulation -- the release of an egg.
After sex, pregnancy may occur if an egg is released and the sperm and egg meet. But the sperm are available inside the woman for days, so a woman who releases an egg one, two or three days after sex can become pregnant. If, however, she takes emergency contraception after sex but before releasing an egg, the emergency contraception will prevent the egg from being released and thus prevent pregnancy. Since pregnancy can result if emergency contraception is taken after an egg has been released, EC is not 100% effective, and it becomes less effective when there is a delay in administering it.
The emergency contraception pill should not be confused with mifepristone (also called Mifeprex, and formerly known as RU-486), an abortifacient which is taken after implantation has occurred, aborting the pregnancy. The morning-after pill must be taken before implantation, or it will have no effect.
Earlier, it was believed that emergency contraception worked by preventing zygotes from implanting in the womb. Today, however, current medical science, as reflected in research papers published in respected medical journals, states that emergency contraception works by preventing ovulation. Recent medical studies in animals (the rat and the monkey) did not suggest that emergency contraception prevents implantation; however, this mechanism of action cannot be ruled out in all cases, as it is impossible to prove a negative.
Although the United States Food and Drug Administration, National Institutes of Health, the American College of Obstetricians and Gynecologists and other health agencies define pregnancy as beginning with implantation, some pro-life medical professionals, outdated embryology texts, and activists argue that preventing implantation is unethical, as the blastocyst (early-stage embryo) then dies instead of growing into a fetus and, ultimately, being carried to term.
In addition, manufacturers of oral contraceptives have long claimed that the Pill provides three lines of defense against pregnancy: it prevents ovulation (most of the time), blocks sperm by thickening cervical mucus, and, should all else fail, theoretically reduces the chances that a fertilized egg will implant in the uterus by hormonally altering the uterine lining.
However, it is not known if this post-fertilization effect actually happens. "There is no evidence that the Pill's effect on the uterine lining interferes with implantation or has a post-fertilization effect," says contraception expert Felicia Stewart, MD, codirector of the Center for Reproductive Health Research and Policy in San Francisco. "Documenting it would be a very difficult research task."
David Grimes, MD, a clinical professor in obstetrics and gynecology at the University of North Carolina School of Medicine, says the Pill and other hormonal contraceptives work primarily by preventing ovulation.
Consensus comes from a surprising source. "The post-fertilization effect was purely a speculation that became truth by repetition," says Joe DeCook, MD, a retired OB/GYN and vice president of the American Association of Pro-Life Obstetricians and Gynecologists. "In our group the feelings are split. We say it should be each doctor's own decision, because there is no proof."
Whether post-fertilization effects would make EC an abortifacient is debated, due to the beginning of pregnancy controversy. Under the standard medical definition of pregnancy starting from implantation, EC is a contraceptive and never an abortifaciant. However, if pregnancy were considered as beginning at fertilization, then EC might sometimes act as an abortifacient.
A Massachusetts law that went into effect on 14 December, 2005, requires all hospitals in the state to provide emergency contraception to any "female rape victim of childbearing age" Commonwealth of Massachusetts Chapter 91 of the Acts of 2005. "An Act Providing Timely Access to Emergency Contraception." Enacted September 15, 2005. Accessed April 28, 2006. including Catholic Hospitals who oppose the provision of emergency contraception. In a letter criticizing the joint UN/WHO Inter-agency Field Manual on Reproductive Health in Refugee Situations, the Catholic Church explains their belief that emergency contraception, along with IUDs and hormonal contraception, cannot be considered "solely contraceptive because in the case of effective fertilisation a chemical abortion would be carried out during the first days of pregnancy."Barragán, Javier L., Hamao, Stephen F., and Trujillo, Alfonsocard L. The Reproductive Health of Refugees. Pontifical Council for the Pastoral Care of Migrants and Itinerant People. September 14, 2001. Accessed April 28, 2006. The Catholic position on family planning is explained further in Ethical and Religious Directives for Catholic Health Care Services."Ethical and Religious Directives for Catholic Health Care Services, Fourth Edition." United States Conference of Catholic Bishops. 2001. Accessed April 28, 2006. Because of this expressed moral stance against emergency contraception, the Massachusetts Catholic Conference opposed this law, stating interference with religious freedom.
Chemical contraception | Hormonal contraception
Pille danach | Anticonceptivo de emergencia | Pilule du lendemain | 사후 피임약 | Pillola del giorno dopo | Morning-afterpil | Jälkiehkäisy
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