Emergency Postcoital Contraception 

Updated: May 14, 2014
  • Author: Kirsten J Sasaki, MD; more...
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Emergency Postcoital Contraception

There are several different formulations of emergency postcoital contraception currently available in the United States. Most options are oral formulations that are most effective when taken immediately after unprotected intercourse but are effective up to 120 hours after intercourse. [1] Options include the following:

  • Progestin
  • Combined estrogen and progestin (Yuzpe regimen)
  • Selective progesterone receptor modulator (ulipristal acetate)

The copper intrauterine device (IUD) is the most effective method of emergency contraception [1] and can be placed up to 120 hours after unprotected intercourse.

Emergency contraception is not effective after implantation has occurred, [2] and the progestin only and combine estrogen-progestin method do not increase risk for current pregnancies. [3, 4]

Candidates for emergency postcoital contraception

Candidates for emergency postcoital contraception include female patients who do not desire pregnancy and have had unprotected or underprotected intercourse within 120 hours (ie, slipped or broken condom, missed active doses of birth control pills, removed intravaginal contraceptive ring for >3 hours during an in-ring week, removed transdermal contraceptive patch for >1 hour during a patch week, missed depot shot).

There are no medical contraindications to the progestin-only or combined estrogen-progestin method of emergency contraception, even in patients who are not candidates for combined oral contraceptives (eg, liver disease, smokers >35 years, hypertension, cardiac disease). [5]

Some formulations require a prescription, but Plan B-One Step is currently available without a prescription.

Methods of emergency postcoital contraception

Progestin-only formulations

One pill

  • Plan B-One Step (1.5 mg levonorgestrel): Available without a prescription on the pharmacy shelf, without age restrictions
  • Next Choice One Way and My Way (1.5 mg levonorgestrel): Available without a prescription on pharmacy shelf to patients aged 17 years or older (identification required)

Two pills

  • Generic levonorgestrel (1.5 mg levonorgestrel total): Available without a prescription to patients aged 17 years or older (identification required); available with a prescription to patients aged 16 years or younger; both pills may be taken at once or (1.5 mg) or one pill (0.75 mg) followed by the second pill (0.75 mg) 12 hours later

Estrogen and progesterone formulations (Yuzpe regimen)

Selective progesterone receptor modulator (ulipristal acetate)

  • No change in efficacy when taken up to 120 hours after unprotected intercourse [1]
  • Single dose of 30 mg
  • Requires prescription by a health care professional
  • Contraindicated in patients with severe kidney or liver disease [6]
  • Limited knowledge on effects of current pregnancy [6, 7]

Copper IUD

  • Inhibits fertilization and/or prevents implantation [8]
  • Provides continued contraception for up to 10 years after placement
  • Requires placement by a healthcare professional

Important notes

Common side effects include the following:

  • Nausea and vomiting: Increased with the Yuzpe method versus levonorgestrel-only method [7] ; if vomiting occurs within 3 hours of taking medication, another dose of medication may be required [9]
  • Headache
  • Bleeding: The patient’s next period may be early or delayed by 1 week owing to the mechanism of emergency contraception; patients without a period within 21 days of undergoing emergency contraception may be pregnant and should contact a healthcare professional
  • Breast tenderness

The patient may still conceive in the same menstrual cycle that she undergoes emergency contraception, so contraception should still be used, and long-term contraceptive options should be considered and discussed with a healthcare professional.

Ulipristal may decrease the efficacy of hormonal contraception, so barrier contraception should be used during that cycle.

Emergency contraception provides no protection against sexually transmitted infections (eg, chlamydia, gonorrhea, HIV infection, syphilis, herpes).

Patients may be directed to the emergency contraception Web site http://ec.princeton.edu (telephone: 888-Not-2-late).