Emergency contraception (EC) can prevent pregnancy soon after unprotected intercourse, sexual assault, or failure or improper use of a birth control method. EC reduces the risk of pregnancy when used up to 120 h (5 days) after unprotected sex but is more effective if used earlier.

• Morning-after pill, postcoital contraception
• EC

Approximately 49% of all pregnancies and more than 82% of teen pregnancies in the U.S. are unintended. An estimated 1.7 million unintended pregnancies could be prevented annually if EC use were widespread.

• •If there is doubt about whether a patient is already pregnant from intercourse that occurred more than 2 wk previously, a pregnancy test may be helpful. However, there is no need for a pregnancy test before administering EC pills. Delays in administration of the medication will reduce its efficacy. The medication in EC pills will not harm an established pregnancy.
• •A pregnancy test should be performed before insertion of an IUD.

• •Administer EC as soon as possible after unprotected intercourse. EC pills function by delaying ovulation, thus it is important to counsel patients to abstain or use a barrier method for 2 wk following EC use in order to avoid a later-cycle pregnancy.
• •Copper IUD for EC:
  1. 1.Emergency insertion of the copper IUD is the most effective option for EC
  2. 2.Highly effective when placed within 5 days of intercourse
  3. 3.Affects sperm viability and function
  4. 4.Ideal for women who desire effective long-term contraception and have no contraindications to IUD insertion
  5. 5.A pregnancy test should be performed before IUD insertion
  6. 6.Requires insertion by a clinician
  7. 7.Some women may experience changes in bleeding patterns that they may find bothersome
  8. 8.Small risk of device expulsion or uterine perforation¹
• •52-mg levonorgestrel IUD:
  1. 1.Emergency insertion of the levonorgestrel IUD is noninferior to the copper IUD when placed as EC²
  2. 2.Highly effective when placed within 5 days of intercourse
  3. 3.Affects follicular rupture and ovulation prior to LH surge
  4. 4.Ideal for women who desire effective long-term contraception and have no contraindications to IUD insertion
  5. 5.A pregnancy test should be performed before IUD insertion
  6. 6.Requires insertion by a clinician
  7. 7.Small risk of device expulsion or uterine perforation¹
• •Emergency contraceptive pills (Table E1):
  1. 1.Ulipristal acetate (Ella):
     1. a.Single dose 30-mg ulipristal acetate, a progesterone-receptor modulator
     2. b.Effective for up to 120 h
     3. c.More effective than levonorgestrel EC; most effective hormonal option
     4. d.Prescription is required
  2. 2.Levonorgestrel (Next Choice, Plan B One-Step):
     1. a.Total dose 1.5-mg levonorgestrel
     2. b.Effective for up to 72 h but best when used as soon as possible
     3. c.A single dose is equally effective and causes no more side effects than two divided doses
     4. d.Less effective in overweight women with BMI >25 and even less effective in obese women (BMI >30) compared to women with BMI <30
  3. 3.Available over the counter without a prescription for all ages. Providing a prescription may decrease the cost of the medication, especially for Medicaid recipients
  4. 4.Combined estrogen/progestin contraceptive pills:
     1. a.Least effective method (56% to 86%) with highest incidence of side effects.
     2. b.Two doses, 12 h apart, of 100 to 120 mcg ethinyl estradiol and 0.5 to 0.6 mg of levonorgestrel (or 1.0 to 1.2 mg of norgestrel) per dose.
     3. c.Prescription is required, but if patient uses combined oral contraceptives, she may have the product on hand.
     4. d.The Emergency Contraception website provides instructions for using available combined oral contraceptive pills for EC.
• •Side effects:
  1. 1.Nausea: Combined estrogen-progestin EC has a higher rate of nausea than ulipristal and levonorgestrel regimens. Side effects resolve within 1 to 2 days. Antiemetics such as meclizine 25 mg orally are recommended 1 h before taking combined estrogen-progestin EC. It can be used on an as-needed basis with the other EC methods.
  2. 2.Irregular bleeding: Many patients may experience irregular bleeding from 1 wk to 1 mo after EC. Irregular bleeding is typically self-limited.
  3. 3.Other side effects include, but are not limited to, headache, fatigue, cramping, and breast tenderness.
• •Contraindications:
  1. 1.Few contraindications to EC exist other than hypersensitivity to the product. EC pills will not affect an established pregnancy.
  2. 2.There are no other evidence-based medical contraindications to the use of EC pills. The benefits of EC in preventing pregnancy generally outweigh the theoretical risks for women with contraindications to long-term use of combined hormonal contraception, such as thromboembolic disease, smoking after age 35 yr, heart disease, or liver disease. Nonestrogen containing EC is preferable for all women because of better efficacy but particularly for those with any of these conditions or who are breastfeeding.

Because EC pills are less effective than other forms of contraception, they are not recommended as an ongoing method of contraception. The copper IUD is highly effective for EC and is approved by the FDA for use up to 10 yr, with data supporting its use up to 12 yr.³ The 52-mg levonorgestrel IUD is also highly effective as EC and is FDA approved to prevent pregnancy for up to 8 yr.

After using EC, most women will have their menses within 1 to 2 wk of the expected date. If a woman’s next expected menses are delayed by more than 3 wk, a pregnancy test should be performed.

• •The copper IUD and 52-mg levonorgestrel IUD are the most effective form of EC and are the only methods that provide users with long-term contraception.
• •All forms of EC pills reduce the risk of pregnancy after unprotected intercourse, with ulipristal acetate being the most effective pill. Delayed ovulation can result in a later-cycle pregnancy, so patients should use a barrier method for 2 wk following EC pill use.
• •The copper IUD and 52-mg levonorgestrel IUD are highly effective regardless of BMI. EC pills are less effective in overweight and obese women, but the weight at which they lose efficacy is unclear and may vary between women. Therefore regardless of BMI, all EC methods should be offered to all women with appropriate counseling that some forms may be less effective with higher BMI. Ulipristal acetate is more effective than levonorgestrel, particularly in overweight and obese women.
• •A pregnancy test is not necessary before administering EC pills because the medications will not harm an existing pregnancy.
• •Advanced prescription of EC pills at routine visits may increase timely use of EC and does not decrease the use of more reliable means of contraception. Health care providers who speak with the pharmacist directly are more likely to ensure timely distribution of EC pills to their patients.
• •Levonorgestrel EC is available in the U.S. without a prescription or proof of age.

• •Women should be counseled about contraceptive options and the availability of EC before it is needed.
• •Patients should begin an effective method of birth control immediately after using EC. Hormonal contraceptives can be started the day after EC is administered. Abstinence or a barrier method should be used for 2 wk.
• •EC should be offered to all women after sexual assault.

• Contraception (Related Key Topic)