Emergency Contraception

• Emergency contraceptive pills (ECPs) provide a short, high dose of combined estrogen and progestin, or progestin alone and are 75% effective in preventing pregnancy within 72 hours after unprotected intercourse

Indications include:

• unprotected intercourse

• failure of a barrier method

• sexual assault

• potential pill failures

• recent use of suspected teratogens

• Emergency contraception works in three ways. It slows down ovulation, it stops the fertilization of the egg, and it stops the attachment of the egg to the wall

• Emergency contraceptive pills do not affect an established pregnancy and numerous studies of the teratologic risk of conception during regular use of oral contraceptives (including the use of older, higher-dose preparations) found no increase in risk.

• Emergency contraception is safe. The ACOG stated in 1996 that no published studies have reported evidenced based criteria contraindicating use of ECPs

• The World Health Organization noted that because ECPs are given over such a short time period, experts believe they have no clinical effect on conditions such as cardiovascular disease, angina, acute focal migraine and severe liver disease.

• Both the World Health Organization, and the International Planned Parenthood Federation have stated that there are no absolute contraindications to use of emergency contraceptive pills except pregnancy

• The pregnancy exception relates to the fact that the regimen is not effective during pregnancy, not to any teratogenic effects

• On February 25, 1997, the FDA announced the use of certain combined oral contraceptives containing ethinyl estradiol and levonorgestrel as safe and effective for the prevention of pregnancy

• The pills are given in two doses. To prevent pregnancy, the first dose of pills must be taken by mouth as soon as possible, ideally within 3 days (72 hours), but no later than 5 days (120 hours) of having unprotected sex. A second dose is taken 12 hours after the first dose. The number of pills in the dose depends on the brand of pill used. For progestin-only pills, both doses can be taken at the same time or 12–24 hours apart

• On September 3, 1998, the Food and Drug Administration (FDA) accepted a commercially available product containing ethinyl estradiol and levonorgestrel designated for use as an emergency contraceptive

• On July 28, 1999 the FDA approved the first progestin-only contraceptive. The new product's efficacy in reducing pregnancies is 83% with less incidence of nausea and vomiting compared to the combined oral contraceptive containing ethinyl estradiol and levonorgesterel.

• There are two distinct pill types, the brand name "Preven" and the brand name "Plan B". Preven contains the same hormones as regular birth control, estrogen and progestin. It causes more instances of nausea and vomiting than Plan Bs, and decreases the chances of pregnancy by 75%. However, Preven can be used as an ongoing form of birth control. Plan B only contains the hormone progestin. It is more effective, decreasing chances of pregnancy by 89%, and has less of a chance for side effects. These pills can be taken immediately after the sex, or up to 72 hours later.

• Dose: Two doses of 100ug ethinyl estradiol and 500ug levonorgestrel taken 12 hours apart. 

• 4 tablets stat of Nordette or Microgynon 30 (or generic equivalent) and another 4 tablets 12 hours later

• As nausea and vomiting are very common with the Yuzpe method, an anti emetic, to be taken 30-60 minutes prior to the hormonal doses, should be supplied/prescribed with this regimen

• Less common side effects including headache, breast tenderness and lower abdominal pain can occur with this method.1

• No adverse effects on foetal development have been reported with the method in cases where pregnancy has occurred

• Two methods of birth control can be used for emergency contraception. The most commonly used method is pills (also known as the “morning-after pill”). Birth control pills contain the hormones estrogen and progestin or, in some cases, progestin only. The progestin-only method is more effective and is less likely to cause nausea. The intrauterine device (IUD) also can be used for emergency contraception

• Dose: Two doses of levonorgestrel 750 ug taken 12 hours apart. 

• Postinor-2 one tablet and another tablet 12 hours later; 

• Microlut or Microval twenty-five (25) tablets and twenty-five (25) tablets 12 hours later.

• Both levonorgestrel and Yuzpe methods have been shown to be most effective when commenced within 12-24 hours of sexual intercourse, with commencement of the first dose recommended before 72 hours

• A recent study, using the Yuzpe regimen, found that emergency contraception may still be effective (though to a lesser degree) in preventing pregnancy, when commenced up to 120 hours after intercourse

The IUD for Emergency

Contraception

• The IUD can be used as emergency contraception. It works best if inserted within 5 days of having unprotected sex. The presence of the IUD prevents the fertilized egg from attaching to the wall of the uterus

• A benefit of the IUD is that it can be left in for long-term use. The IUD may be a good choice if you cannot take birth control pills. The IUD does not prevent sexually transmitted diseases

• Copper bearing IUCDs provide an effective method of postcoital contraception. The failure rate is less than 1%. Careful assessment and counselling should take place before insertion is decided upon. The IUCD is not suitable for women who have risk factors for pelvic inflammatory disease

• An emergency IUCD can be inserted at any time in the cycle provided the earliest episode of unprotected intercourse occurred no more than 5 days previously. Where the earliest episode of unprotected intercourse was more than 5 days previously, an IUCD can be considered up to 5 days after the calculated earliest day of ovulation (ie. up to day 19 of a 28 day shortest cycle by history)

• This limit is well within the period before implantation. If the woman does not wish to continue using the IUCD as a contraceptive method, it may be removed at the time of the next period. If hormonal contraception has been commenced, the IUCD may be removed after 7 active pills have been taken

Frequency of Use

• Emergency contraceptive pills (ECP) should not replace the use of regular contraception, as the cumulative pregnancy rate for frequent use of ECP is higher than with regular contraception. However, if unprotected sex occurs in a cycle where the ECP has already been used it can be used again

• Women should understand that the use of the ECP cannot protect them from the possibility of pregnancy if unprotected intercourse occurs later in the cycle.

• In cycles, where unprotected intercourse has occurred more than once, ECP can be used, although efficacy will be influenced by the time interval since the first act of unprotected intercourse. The woman must understand that, if a pregnancy has already occurred, the ECP will not be effective

Drug interactions

Hepatic enzyme inducing drugs• Hepatic enzyme inducing drugs enhance the

metabolism of levonorgestrel and ethinyl estradiol. If a woman taking these drugs (e.g. phenytoin, carbamazepine, rifampicin, griseofulvin) uses emergency hormonal contraception the recommendation is to double each dose. This increases the risk of side effects

Antibiotics

• Antibiotics taken concurrently with hormonal emergency contraception are unlikely to alter its efficacy and no alteration in dose is advised. The exceptions are the enzyme inducers rifampicin and griseofulvin as detailed above