Emergency contraception

Abstract

Objective: To review current knowledge about emergency contraception (EC), including available options, their modes of action, efficacy, safety, and the effective provision of EC within a practice setting.

Options: The combined estradiol-levonorgestrel (Yuzpe regimen) and the levonorgestrel-only regimen, as well as post-coital use of copper intrauterine devices, are reviewed.

Outcomes: Efficacy in terms of reduction in risk of pregnancy, safety, and side effects of methods for EC and the effect of the means of access to EC on its appropriate use and the use of consistent contraception.

Evidence: Studies published in English between January 1998 and March 2010 were retrieved though searches of Medline and the Cochrane Database, using appropriate key words (emergency contraception, post-coital contraception, emergency contraceptive pills, post-coital copper IUD). Clinical guidelines and position papers developed by health or family planning organizations were also reviewed.

Values: The studies reviewed were classified according to criteria described by the Canadian Task Force on Preventive Health Care, and the recommendations for practice were ranked according to this classification (Table 1).

Benefits, harms, and costs: These guidelines are intended to help reduce unintended pregnancies by increasing awareness and appropriate use of EC.

Sponsor: The Society of Obstetricians and Gynaecologists of Canada. Summary Statements 1. Hormonal emergency contraception may be effective if used up to 5 days after unprotected intercourse. (II-2) 2. The earlier hormonal emergency contraception is used, the more effective it is. (II-2) 3. A copper IUD can be effective emergency contraception if used within 7 days after intercourse. (II-2) 4. Levonorgestrel emergency contraception regimens are more effective and cause fewer side effects than the Yuzpe regimen. (I) 5. Levonorgestrel emergency contraception single dose (1.5 mg) and the 2-dose levonorgestrel regimen (0.75 mg 12 hours apart) have similar efficacy with no difference in side effects. (I) 6. Of the hormonal emergency contraception regimens available in Canada, levonorgestrel-only is the drug of choice. (I) 7. A pregnancy that results from failure of emergency contraception need not be terminated (I) Recommendations 1. Emergency contraception should be used as soon as possible after unprotected sexual intercourse. (II-2A) 2. Emergency contraception should be offered to women if unprotected intercourse has occurred within the time it is known to be effective (5 days for hormonal methods and up to 7 days for a copper IUD). (II-2B) 3. Women should be evaluated for pregnancy if menses have not begun within 21 days following emergency contraception treatment. (III-A) 4. During physician visits for periodic health examinations or reproductive health concerns, any woman in the reproductive age group who has not been sterilized may be counselled about emergency contraception in advance with detailed information about how and when to use it. (III-C).