CHAPTER 92
“Morning After” Emergency Contraception
Presentation
A woman had unprotected sexual intercourse in the past 24 to 72 hours and wants to prevent an unplanned pregnancy. Emergency contraception is not a primary form of birth control. However, this may be needed by a female who forgot to take her oral birth control pills or had the condom break during intercourse, or many other scenarios in which the usual method of birth control failed or was misused. This also may be part of the prophylactic treatment of a rape victim.
What To Do:
If there is any possibility of a preexisting pregnancy, obtain a pregnancy test. If the test is already positive, the following measures will not be effective for terminating that pregnancy.
When a preexisting pregnancy is not an issue, suggest or prescribe a contraceptive in large doses for a short time to prevent implantation. Note that emergency contraception is approved for sale by the U.S. Food and Drug Administration (FDA) over the counter for men and women older than the age of 17 years; a prescription is not needed unless the man or woman is age 16 or younger. In some states, the pharmacist may have special arrangements with prescribers who are seen by women younger than 16 years of age.
Emergency contraception is most effective when taken as soon as possible but will be effective up to 5 days (120 hours) after unprotected intercourse.
Expect some nausea. Prescribe an antiemetic if needed; estrogen-containing pills do tend to have more nausea and vomiting associated with their use than progestin-only pills.
Examples include one of the following:
Levonorgestrel tablets, 0.75 mg (Plan B or Next Choice, 2-tablet packs); take the first tablet as soon as possible within 120 hours of unprotected sex, and take the second tablet 12 hours after taking the first tablet. Plan B One-Step has been found to be just as effective as a single 1.5-mg dose; thus one could take the two 0.75-mg tablets as a single dose as well.
Patients who vomit within 1 hour of taking either dose can repeat it, but, of course, that would require buying another package.
Emergency contraceptive kit (Preven Kit) contains four pills of levonorgestrel and ethinyl estradiol, along with a patient information book and urine pregnancy test.
When standard birth-control pills are a more available option for the patient, have her take norgestrel and ethinyl estradiol (Ovral), PO—two now and two in 12 hours, or four pills now and four in 12 hours of lower dose contraceptives (Levlen, Lo/Ovral, Nordette, Tri-Levlen, or Triphasil).
Ulipristal acetate (Ella, EllaOne) is not a hormone. It works on progesterone, by preventing the progesterone from having its normal effects on the uterus and ovulation. It is taken as a single 30-mg tablet. This may be more effective than the levonorgestrel tablets for those in the 72- to 120-hour postevent window.
Ask about exposure to sexually transmitted diseases, which might require separate testing and prophylaxis.
When appropriate, take this opportunity to teach about safe sex and pregnancy prevention.
Arrange for follow-up if this treatment fails to prevent pregnancy.
What Not To Do:
Do not prescribe emergency contraception if the patient is already pregnant; it will not work.
Do not prescribe emergency contraception if the patient has unexplained vaginal bleeding. Assess for sexual assault. Consider if referral to a sexual assault nurse examiner is needed or obtain gynecologic consultation.
Discussion
Hormonal emergency contraception is a safe and effective method to prevent pregnancy after unprotected intercourse, contraceptive failure, or sexual assault. Emergency contraception involves a higher dose of combined estrogen and progestin, or progestin-only, oral contraceptive pills. The levonorgestrel-only formulation (Plan B) causes less nausea and vomiting than combination hormonal regimens. Headache, abdominal pain, and breast tenderness can also occur.
There is currently no evidence, despite numerous studies worldwide, that emergency contraception fosters unsafe sex and decreased rates of use of barrier methods of birth control, which would also protect a woman against sexually transmitted diseases, either in adolescents or in adult women.
Unprotected intercourse 3 days before ovulation results in pregnancy in approximately 15% of women, 1 or 2 days before ovulation in approximately 30%, and on the day of ovulation in approximately 12%. More than 2 days after ovulation, the probability of pregnancy approaches zero. The risk for pregnancy following sexual assault is approximately 5% in victims of reproductive age.
Emergency contraception can reduce the risk for pregnancy by at least 75%, depending on the regimen used and timing of treatment. Using the emergency contraceptive pills at any time during the cycle, research demonstrates less than a 1 in 30 chance of pregnancy (0.03%). Hormonal contraception preparations are more effective the earlier after unprotected intercourse they are taken and are recommended for use within 120 hours. The mechanism of action of hormonal contraception preparations is complex; they may interfere with ovulation, fertilization, or implantation. What is clear is that they do not interrupt an established (implanted) pregnancy, nor are they teratogenic.
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