Emergency Contraception

Emergency contraception is the use of a contraceptive method after unprotected intercourse or a recognised method failure to prevent pregnancy. Four options exist: the copper intrauterine device (IUD), ulipristal acetate 30 mg, levonorgestrel 1.5 mg and the combined oral contraceptive (Yuzpe) regimen. Oral options prevent about 75 to 95% of expected pregnancies, and each works better the earlier it is taken. None is a regular method, and none protects against sexually transmitted infections or HIV.

Pregnancy risk addressed. One act of unprotected intercourse in the second or third week of the cycle carries about 8 pregnancies in 100 women. After oral emergency contraception this falls to 1 to 2 in 100. The denominator is one episode of intercourse, not a year of use.

Indications.

• Intercourse without contraception, and sexual assault.

• Condom breakage, slippage, spillage or incorrect use.

• Three or more missed combined pills, or other hormonal methods used outside their grace windows.

• IUD expulsion.

• Failed withdrawal.

• Intercourse in the fertile phase while relying on fertility awareness.

Mechanism. Oral options prevent or delay ovulation and may slow ovum transport. They do not work once ovulation has occurred and do not disrupt an established pregnancy. The copper IUD is toxic to sperm and ovum and prevents fertilisation.

Options compared.

Return to fertility. Immediate. An oral dose delays ovulation but does not protect for the rest of the cycle, so later intercourse in the same cycle can still cause pregnancy.

Most patients can use emergency contraception safely, including those who cannot use ongoing hormonal methods. There is no age or parity limit. No examination or laboratory test is needed before an oral dose.

Category 1 (no restriction). Breastfeeding (with levonorgestrel), previous ectopic pregnancy, sexual assault, obesity, and use of enzyme inducers such as rifampicin, rifabutin, phenytoin, phenobarbital, carbamazepine, efavirenz and nevirapine.

Category 2 (advantages outweigh risks). Breastfeeding with ulipristal acetate, previous ischaemic heart disease, stroke or other thromboembolic disease, angina, migraine, and severe liver disease including jaundice. Give without delay in these groups. Waiting beyond 120 hours removes the benefit, and pregnancy carries more risk than one course.

Known pregnancy. Not indicated. Accidental use causes no known harm to the patient, the pregnancy or the foetus.

History. Hours since the episode and number of episodes; first day of the last menstrual period and cycle regularity; method in use and the nature of the failure; earlier emergency contraception this cycle; weeks since delivery and breastfeeding status; body weight; enzyme-inducing medicines; liver, migraine and cardiovascular history; possible sexual assault.

Choosing the option.

• Offer the copper IUD first when within 5 days and acceptable to the patient. It is the most effective option and gives long-term contraception.

• Offer ulipristal acetate when the IUD is declined or unavailable, especially 72 to 120 hours after intercourse, near ovulation or at higher body weight.

• Offer levonorgestrel when ulipristal acetate is unavailable, or when breastfeeding.

• Use the Yuzpe regimen only when nothing else can be obtained.

Counselling points for the clinician. Obtain consent, protect confidentiality and exclude coercion. Under 18 years give assent, with consent in line with the law; do not withhold the method on age alone. Offer condoms for dual protection. After sexual assault, offer HIV post-exposure prophylaxis within 72 hours, presumptive treatment for sexually transmitted infections and psychosocial support at the same visit.

Special groups.

• Postpartum: emergency contraception is not needed before 4 weeks after birth; from 4 weeks it is given like any other patient. The copper IUD can be placed within 48 hours of birth or from 4 weeks.

• Postabortion: ovulation can return within 2 weeks, so emergency contraception may be needed.

• Obesity and enzyme inducers: oral options lose effect, and the copper IUD is preferred.

• HIV, tuberculosis and epilepsy are common reasons for enzyme-inducing treatment and should be asked about directly.

Regimens.

• Copper IUD: copper T 380A, inserted once within 5 days of intercourse or within 5 days of expected ovulation. Protection is immediate, needs no backup and lasts up to 12 years. No drug interactions. No missed-dose rule applies.

• Ulipristal acetate: 30 mg tablet by mouth as one dose, as soon as possible within 120 hours. It is not repeated for the same episode. A progestin is not started for 5 days afterwards. Strong enzyme inducers lower its effect.

• Levonorgestrel: 1.5 mg by mouth as one dose (two 750 microgram tablets together, preferred), as soon as possible within 120 hours. Alternatively 750 micrograms, then a further 750 micrograms 12 hours later. Enzyme inducers and higher body weight lower its effect.

• Yuzpe: monophasic combined pills giving about 100 micrograms ethinylestradiol with 500 micrograms levonorgestrel in each dose, repeated after 12 hours, within 120 hours.

Pregnancy exclusion. Pregnancy is reasonably excluded when there has been no unprotected intercourse since the last normal menses and menses are not overdue. A test is not needed before an oral dose after one recent episode. Give the dose even when pregnancy cannot be excluded, and test if menses are more than 7 days late.

Vomiting. If vomiting occurs within 2 hours of an oral dose, repeat the dose with an antiemetic. If vomiting continues, place the repeat tablets high in the vagina. After more than 2 hours, no extra dose is needed.

Starting ongoing contraception.

Follow up. No routine visit is needed. Advise return if menses are more than 7 days late, bleeding is unusually light, or lower abdominal pain develops. Test for pregnancy 3 weeks after the episode if menses have not started.

Antiemetic regimen. Ondansetron 4 mg by mouth as one dose, repeated once after 8 hours if needed. Maximum 12 mg in 24 hours, for no more than 2 days. Limit to 8 mg in 24 hours in severe liver disease. No kidney adjustment is needed. Avoid in congenital long QT syndrome. In pregnancy use only when the benefit is clear. Short courses are acceptable in breastfeeding.

Copper IUD effects. Cramping, and heavier or longer menses in the first 3 to 6 months. Expulsion, infection and uterine perforation are uncommon and need prompt assessment.

Failure. Menses may come a few days early or late. A pregnancy after failure is not harmed by the dose. After a copper IUD failure, a larger share of pregnancies are ectopic, so assess for ectopic pregnancy.

Referral and escalation. Refer for severe lower abdominal pain, fainting, a positive pregnancy test with pain or bleeding, fever with pelvic pain after IUD insertion, or sexual assault needing full care.

Repeated use. Frequent use is a sign that the patient needs a regular method. Repeated use may harm patients who fall in category 3 or 4 for hormonal methods, so offer the copper IUD to them.