Rationale:

• Single-dose levonorgestrel, available as Plan B in the U.S., prevents 89% of pregnancies that would have otherwise occurred and causes fewer side effects than the other postcoital contraception regimens.

Evidence:

• One review study concluded that as many as 22,000 rape-related pregnancies could be prevented yearly if all women who were raped received prompt medical services and, if not already protected against pregnancy, were provided with emergency contraceptive treatment (80).
• A review of eight efficacy studies estimates that the combination of ethinyl estradiol and a progestin, known as the Yuzpe regimen, prevents approximately 74% of pregnancies that would have otherwise occurred (81).
• One randomized large-scale prospective clinical trial of 1955 women showed that the progestin-only regimen, available as Plan B in the U.S., prevents significantly more than the Yuzpe regimen (82).
• A randomized, double-blind trial in 15 family-planning clinics in 10 countries involving 4136 healthy women found that the progestin-only regimen (Plan B) may be given in a single dose of two pills with efficacy equal to the old two-dose plan (83).
• A prospective observational study of 111 women showed that emergency contraception retains its usual efficacy up to 120 hours after coitus (83; 84).

Comments:

• Plan B is currently FDA approved for postcoital contraception and is available without a prescription to persons aged 18 years and older. All available evidence proves no untoward effects on the fetus should pregnancy occur despite postcoital contraception. The common practice of obtaining written patient consent for these medications seems unwarranted.