Levonorgestrel for emergency contraception fact sheet fact sheet Emergency contraception refers to back- – dislodgment, breakage, tearing, or early October 2005 up methods for contraceptive emergencies removal of a diaphragm or cervical cap which women can use within the fi rst few – failed coitus interruptus (e.g., ejacula- days after unprotected intercourse to pre- tion in vagina or on external genitalia) vent an unwanted pregnancy. Emergency – failure of a spermicide tablet or fi lm to contraceptives are not suitable for regular melt before intercourse use. – miscalculation of the periodic The WHO-recommended regimen for emer- abstinence method or failure to abstain gency contraception is: on fertile day of cycle • 1.5 mg levonorgestrel as a single dose. – IUD expulsion; • in cases of sexual assault when the Who needs emergency contraception? woman was not protected by an effec- Any woman of reproductive age may need tive contraceptive method. emergency contraception at some point to avoid an unwanted pregnancy. It is meant Mode of action to be used in situations such as: Levonorgestrel emergency contraceptive • when no contraceptive has been used; pills (ECPs) have been shown to prevent • when there is a contraceptive failure or ovulation and they did not have any detect- incorrect use, including: able effect on the endometrium (uterine – condom breakage, slippage, or incor- lining) or progesterone levels when given rect use after ovulation. ECPs are not effective once – three or more consecutive missed the process of implantation has begun, and combined oral contraceptive pills will not cause abortion. – progestogen-only pill (minipill) taken morethan three hours late Effectiveness Based on reports from four studies includ- – more than two weeks late for a pro- ing almost 5000 women, the levonorgestrel gestogen-only contraceptive injection regimen used within 5 days after unpro- (depot-medroxyprogesterone acetate or tected intercourse reduced a woman’s norethisterone enanthate) chance of pregnancy by 60-90 per cent. – more than seven days late for a The regimen is more effective the sooner combined estrogen-plus-progestogen after intercourse it is taken. monthly injection – dislodgment, delay in placing, or early removal of a contraceptive hormonal skin patch or ring Fact sheet scale none_EC.indd 1 10/02/2006 14:41:38 UNDP/UNFPA/WHO/World Bank • Special Programme of Research, Devleopment and Research Training in Human Repoduction Medical eligibility criteria Further reading 6. WHO. Medical eligibility criteria for Emergency contraceptive pills prevent 1. Marions L, Hultenby K, Lindell I et al. contraceptive use. Third edition. pregnancy. They should not be given to a Emergency contraception with mifepris- Geneva, 2004. woman who already has a confi rmed preg- tone and levonorgestrel: mechanism nancy. However, if a woman inadvertently of action. Obstetrics and Gynecology, 7. WHO. Selected practice recommenda- takes the pills after she became pregnant, 2002;100:65–71. tions for contraceptive use. Second the limited available evidence suggests that edition. Geneva, 2005. the pills will not harm either the mother or 2. Durand M, del Carmen Cravioto M, her fetus. Raymond EG et al. On the mechanisms of action of short-term levonorgestreol Emergency contraceptive pills are for administration in emergency contracep- emergency use only and not appropriate tion. Contraception, 2001;64:227–34. for regular use as an ongoing contraceptive method because of the higher possibility of 3. Croxatto HB, Brache V, Ravez M et al. failure compared to modern contraceptives. Pituitary-ovarian function following the In addition, frequent use of emergency standard levonorgestrel emergency con- contraception results in more side-effects, traceptive dose or a single 0.75 mg dose such as menstrual irregularities. However, given on the days preceding ovulation. their repeated use poses no known health Contraception, 2004;70:442–50. risks. 4. Emergency Contraceptive Pills: Medical and service delivery guidelines. Second Edition, 2004. International Consortium for Emergency Contraception, Washington DC, USA. 5. von Hertzen H, Piaggio G, Ding J. et al. Low dose mifepristone and two regimens of levonorgestrel for emergency contraception: a WHO multicentre randomized trial. Lancet, 2002;360:1803–10. Department of Reproductive Health and Research World Health Organization Avenue Appia 20, CH-1211 Geneva 27, Switzerland Fax: +41 22 791 4189 / 4171, E-mail: [email protected] Internet address: www.who.int/reproductive-health Fact sheet scale none_EC.indd 2 10/02/2006 14:41:39.