PRACTICE RECOMMENDATIONS
• Offer emergency contraception (EC) to any woman who reports contraceptive failure or unprotected intercourse within the last 5 days; no clinical exam is necessary. B
• Prescribe a progestin-only EC or ulipristal acetate, both of which are more effective and have fewer adverse effects than an estrogen-progestin combination. A
• Consider giving sexually active teens <17 years an advance prescription for EC, as it is not available over the counter to this age group. C
Strength of recommendation (SOR)
A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series
The average American woman will spend more than 30 years of her life trying to prevent pregnancy—not always successfully. Each year, half of the approximately 6 million pregnancies in the United States are unintended.1 Emergency contraception (EC) gives a woman a second chance to prevent pregnancy after a contraceptive failure or unprotected sex. But all too often, it isn’t offered and she doesn’t request it.
Lack of knowledge about EC continues to be a barrier to its use. Some women have heard about the “morning after pill,” but may not know that EC can be effective for up to 5 days after intercourse—or even that it’s available in this country.2 Others are unaware that it is possible to prevent pregnancy after intercourse,2 and mistakenly believe that EC drugs are abortifacients. In fact, they work primarily by interfering with ovulation and have not been found to prevent implantation or to disrupt an existing pregnancy.3-5
Providers also contribute to the limited use of EC, often because they’re unfamiliar with the options or uncomfortable discussing them with patients, particularly sexually active teens.2
This update can help you clear up misconceptions about EC with your patients. It also provides evidence-based information about the various types of EC, a review of issues affecting accessibility, and a telephone triage protocol to guide your response to women seeking postcoital contraception.
EC today: Plan B and beyond
Hormonal EC was first studied in the 1920s, when researchers found that estrogenic ovarian extracts interfered with pregnancy in animals. The first regimen was a high-dose estrogen-only formulation. In 1974, a combined estrogen-progestin replaced it. Known as the Yuzpe method for the physician who discovered it,6 this regimen used a widely available brand of combined estrogen-progestin oral contraceptive pills. The standard dose consisted of 100 mcg ethinyl estradiol (EE) and 0.5 mg levonorgestrel (LNG) taken 12 hours apart.2,7
Although the Yuzpe method is still in use, progestin-only EC—Plan B as well as generic (Next Choice) and single-dose (Plan B One-Step) LNG formulations—has become the standard of care because it has greater efficacy and fewer adverse effects.2 There are 2 additional options: the copper intrauterine device (IUD), which is highly effective both as EC and as a long-term contraceptive,6 and ulipristal acetate (UPA), which received US Food and Drug Administration (FDA) approval in 2010. This second-generation antiprogestin, sold under the brand name Ella, is well tolerated and highly effective.8
EC efficacy: What the evidence shows
EC is most likely to work when used within 24 hours, but remains effective—albeit to varying degrees—for up to 120 hours (TABLE).2,5,8,9 Thus, which EC is best for a particular patient depends, in part, on timing.
TABLE
Emergency contraception: Comparing methods*2,5,8,9
| EC method | Dose and timing | Benefits | Adverse effects/ drawbacks |
|---|---|---|---|
| Estrogen-progestin OCs | 100 mcg EE and 0.5 mg LNG, taken 12 h apart First dose within 72 h | Easily accessible and widely available; patient may use OCs she already has at home | Higher rates of adverse effects, including nausea, vomiting, headache; less effective than other methods |
| Progestin-only (Plan B, Next Choice, others) | 1.5 mg LNG within 72 h (available in divided doses or in a single tablet; 2 tablets may be taken as a single dose) | Available OTC for patients ≥17 y; more effective and fewer adverse effects than estrogen-progestin Convenience of single dose | Prescription required for patients <17 y Approved for use within 72 h; effectiveness diminishes thereafter |
| UPA (Ella) | 30 mg UPA, taken ≤120 h† | More effective than LNG; fewer adverse effects than estrogen-progestin Efficacy remains high ≤5 days Convenience of single dose | Prescription required; not available at all pharmacies Not studied in breastfeeding‡ |
| Copper IUD | Insert ≤120 h | Extremely effective Provides immediate, long-term contraception | Insertion requires staff training; higher cost than oral EC |
| EC, emergency contraception; EE, ethinyl estradiol; IUD, intrauterine device; LNG, levonorgestrel; OCs, oral contraceptives; OTC, over the counter; UPA, ulipristal acetate. *Low doses of mifepristone (<25-50 mg)—approved as an abortifacient in much larger doses—may also be used as EC. †Dosage should be repeated if vomiting occurs within 3 hours. ‡Advise patients to avoid breastfeeding for 36 hours | |||
Copper IUDs have the highest success rate: Studies have found the copper IUD to be >99% effective in preventing pregnancy when inserted within 5 days of unprotected intercourse.9,10 The copper ions it contains have a toxic effect on sperm, and impair the potential for fertilization; the device may also make the endometrium inhospitable to implantation.9,10