Oral contraceptives are prescribed daily, yet emergency contraception options often are overlooked. Emergency contraception is used to prevent pregnancy after an unprotected or inadequately protected act of sexual intercourse. An open, informative conversation is an important way to increase awareness and knowledge to avoid unintended pregnancies.
Emergency contraception works by inhibiting or delaying ovulation and possibly by inhibiting implantation of the fertilized egg. It is effective only before a pregnancy is established – in the 5 days between intercourse and implantation of the fertilized egg – and is ineffective after implantation. There are no known risks to an established pregnancy or harm to the developing embryo, nor any increased risk for a future ectopic pregnancy.
Dr. Neil Skolnik and Dr. Chelsea Ward.
The most commonly used regimens are combined estrogen-progestin and progestin-only pills. Ulipristal acetate, a progesterone agonist/antagonist, was approved for emergency contraception in 2010.
The estrogen-progestin regimen uses various oral contraceptive products in doses that are equal to two doses of 100 mcg of ethinyl estradiol plus 0.5 mg of levonorgestrel, taken as soon as possible after intercourse, up to 72 hours, with a second dose 12 hours after the first dose.
The progestin-only regimen contains 1.5 mg levonorgestrel in single-dose or two-dose protocols and can be acquired over the counter for women age 17 years and older; patients younger than 17 years require a prescription. The manufacturers of the progestin-only regimen are phasing out the two-dose protocol, because studies have shown that taking 1.5 mg one time is equally as effective as two 0.75-mg pills 12 hours apart.
Recent studies have shown that emergency contraception is modestly effective up to 5 days after intercourse. The newest approved regimen contains 30 mg of ulipristal acetate in a single dose, and studies have shown effectiveness for up to 5 days after intercourse.
It is estimated that emergency contraception can prevent approximately 75% of pregnancies that would otherwise occur, and the levonorgestrel-only regimen is approximately 50% more effective than the combined regimen.
Side effects from emergency contraception are short term in nature, with no serious side effects. Nausea and vomiting are most common and are found more often with the estrogen-progestin regimen than with the levonorgestrel or ulipristal acetate regimens. It is recommended that an antiemetic be prescribed prophylactically if the combined regimen is given. Irregular bleeding can occur with all of the regimens during the month after treatment. Other side effects include breast tenderness, dizziness, headache, cramping, and fatigue.
There are also no health conditions that are contraindications for emergency contraception, even those that would otherwise be a contraindication for oral contraception. No clinical examination or pregnancy testing is necessary before dispensing a prescription of emergency contraception – unless the woman was a victim of assault, when further sexually transmitted disease testing and counseling are important.
Emergency contraception may be used more than once, even within the same menstrual cycle; but it is not intended and not recommended to be used as long-term contraception.
Use of a copper intrauterine device (IUD) for emergency contraception has been reported since 1976, and has pregnancy rates of 0%-0.2% if inserted within 5 days of intercourse. The advantage of insertion of the copper IUD is that it can be retained for long-term contraception. Women who meet the standard criteria for insertion of an IUD and do not have any medical indications that would prohibit them from using the copper device may choose this alternative to hormonal treatment, although the risks and costs must be considered.
Because emergency contraception delays ovulation, it is possible that a woman can become pregnant later in the menstrual cycle. Women should begin using barrier contraceptives immediately after using emergency contraception to prevent pregnancy until normal menses resumes. Long-term hormonal methods – IUD, oral, Depo-Provera, or implant – should be administered after the next menstrual period, once it is confirmed that the patient is not pregnant.