postcoital contraception


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morning-after pill (MAP),

an oral drug that, when taken by a woman within 2-3 days after intercourse, reduces the probability that she will become pregnant.

The U.S. Food and Drug Administration (FDA) has approved two regimens for postcoital contraception. The Yuzpe regimen consists of a combination of progestogen (levonorgestrol 0.25 mg or norgestrel 0.5 mg) and estrogen (ethinyl estradiol 100 mcg) taken at once and repeated in 12 hours. Alternatively, two doses of levonorgestrel 0.75 mg may be taken without estrogen. With either regimen, the first dose should preferably be taken within 24 hours after intercourse, and not more than 72 hours after. The Yuzpe method reduces the likelihood of pregnancy by about 57%, the levonorgestrel method by 85%. About 50% of women experience uterine bleeding within 1 week and most of the rest within 3 weeks unless conception has occurred. If taken early enough, the hormones may prevent fertilization by altering tubal function or exerting toxicity against the ovum. Probably, however, they usually act by preventing implantation of a fertilized ovum. This is not emergency contraception but rather chemical abortion. The incidence of nausea is about 40% with levonorgestrel alone and about 65% with the Yuzpe regimen. Headache, fluid retention, and breast tenderness may also occur. This procedure is contraindicated in women for whom oral contraceptives are contraindicated, such as those with hypertension or a history of stroke or thromboembolic disease. The short course of high-dose hormones probably does not interrupt a pregnancy after implantation has occurred, and there is no evidence that fetal harm has occurred when such a pregnancy has continued to term. However, hormone use is contraindicated in known pregnancy or if the woman has had unprotected intercourse within the preceding 3-10 days. An application for over-the-counter marketing of levonorgestrel has been denied by the FDA.

Farlex Partner Medical Dictionary © Farlex 2012

morn·ing af·ter pill

(mōr'ning af'tĕr pil)
An oral medication, consisting of two pills taken 12 hours apart that, when taken by a woman within 2-3 days after intercourse, reduces the probability that she will become pregnant.
Synonym(s): emergency contraceptive, emergency hormonal contraception, postcoital contraception.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

postcoital contraception

The use of any measure to prevent pregnancy after sexual intercourse has occurred. Such measures are not strictly contraceptive as they are likely to act after conception has occurred. They include taking two high-dose contraceptive pills as soon as possible and then 12 hours later; the taking of a single dose of mifepristone; and the insertion of a copper-releasing IUCD. Mifepristone is currently not licensed anywhere outside China for postcoital contraception. Also known as emergency contraception or the ‘morning after pill’.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
References in periodicals archive ?
(1983), "Mode of Action of DL-norgestrel and Ethinylestradiol Combination in Postcoital Contraception. m Effect of Preovulatory Administration Following the Luteinizing Hormone Surge on Ovarian Steroidogenesis," Fertil Steril.
Although progestins were among the first drugs used in postcoital contraception, few studies of the emergency levonorgestrel regimen have controlled for cycle day of unprotected intercourse.
(3.) National Women's Health Network, "Postcoital Contraception: Time for Cautious Approval," Washington.
Clinicians providing family planning services may prescribe an appropriate dosage of oral contraceptive pills as safe and effective emergency postcoital contraception. This study did not demonstrate any significant benefits or risks to providing the pills to patients in advance for self-administration.
Postcoital contraception was first developed in China in the 1970s, primarily for use by married couples living at a distance from one another.
Kaplan, "Endometrial Suction in Luteal Phase as a Method of Late Postcoital Contraception," Contraception, 47:469-474, 1993.
In 1974, Yuzpe and colleagues first published findings on the use of combined estrogen-progestin OCs for postcoital contraception. (2) At the same time, Kesseru and colleagues were evaluating progestin-only regimens for the same purpose.
Such pregnancies are, in part, preventable and such prevention could result in a major reduction in either the number of unwanted pregnancies or pregnancy terminations if an effective method of pregnancy interception (postcoital contraception) were readily available to women.
In his original pilot study of postcoital contraception, Yuzpe used a single dose that was equivalent to one of the two doses in the current therapy, and women were treated up to five days following unprotected inter-course.
OBJECTIVE: A major reduction in the number of unwanted pregnancies and pregnancy terminations could be achieved if an effective method of emergency pregnancy interception (postcoital contraception) was readily available to women.
Grahame, ed., Postcoital Contraception: Methods, Services and Prospects, Pregnancy Advisory Service, London, 1983, pp.
Glasier et al., "Mifepristone Compared with High-Dose Estrogen and Progestogen for Emergency Postcoital Contraception," New England Journal of Medicine, 327:1041-1044, 1992.