Emergency contraception overview
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [2]
Overview
Emergency contraception (EC), or emergency postcoital contraception, refers to contraceptive measures that, if taken after sex, may prevent pregnancy. As its name implies, EC is intended for occasional use, when primary means of contraception fail. Since EC methods act before implantation, they are medically and legally considered forms of contraception. Some pro-life groups define pregnancy as beginning with fertilization, and consider EC to be an abortifacient.
Historical Perspective
Interest in synthetic hormones as postcoital contraceptives originated several decades ago, with the first published study on the subject appearing in 1967.[1] A few different drugs were studied, with a focus on high-dose estrogens, and it was originally hoped that postcoital contraception would prove viable as anongoing contraceptive method.[2]
Classification
Emergency Contraceptive Pills
Emergency contraceptive pills (ECPs)—sometimes simply referred to as emergency contraceptives (ECs) or the morning-after pill —are drugs that act both to preventovulation or fertilization and possibly post-fertilization implantation of a blastocyst (embryo). Emergency contraceptive pills (sometimes referred to as emergency hormonal contraception (EHC) in the U.K.) may contain higher doses of the same hormones (estrogens, progestins, or both) found in regular combined oral contraceptive pills. Taken after unprotected sexual intercourse, such higher doses may prevent pregnancy from occurring.Mifepristone is another kind of ECP, but is considered an anti-hormonal drug, and does not contain estrogen or progestins. The phrase "morning-after pill" is figurative; ECPs are licensed for use up to 72 hours after sexual intercourse. ECPs are distinct from medical abortionmethods that act after implantation.[3]
Intrauterine Devices
Intrauterine devices are usually used as a primary contraception method, but sometimes used as emergency contraception. The copper-T intrauterine device (IUD) 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 with normal IUD use. IUDs may be left in place following the subsequent menstruation to provide ongoing contraception (3-10 years depending upon type).[4]
References
- ↑ "Postcoital contraception". IPPF Med Bull. 1 (4): 3. 1967. PMID 12254703.
- ↑ Demers L (1971). "The morning-after pill". N Engl J Med. 284 (18): 1034–6. PMID 5553470.
- ↑ A minority view in the medical community, along with many pro-life advocates, argue for a different definition of pregnancy; see Controversy section for more detail.
- ↑ Gottardi G, Spreafico A, de Orchi L (1986). "The postcoital IUD as an effective continuing contraceptive method". Contraception. 34 (6): 549–58. PMID 3549140.