From the Guidelines
The most effective emergency contraception option is the copper intrauterine device (IUD), which can be inserted up to 5 days after unprotected intercourse and provides ongoing contraception for up to 10 years, as supported by the U.S. Selected Practice Recommendations for Contraceptive Use, 2013 1. Emergency contraception refers to methods used to prevent pregnancy after unprotected sex or contraceptive failure.
Options for Emergency Contraception
- The copper intrauterine device (IUD) can be inserted within 5 days of the first act of unprotected sexual intercourse as an emergency contraceptive, and its effectiveness is not reduced by the user's weight 1.
- Hormonal emergency contraception pills include ulipristal acetate (ella), taken as a single 30mg tablet within 5 days of unprotected sex, and levonorgestrel (Plan B One-Step, Take Action), taken as a single 1.5mg tablet within 3 days, with ulipristal acetate being more effective than levonorgestrel formulations after the first 72 hours and for women who are overweight or obese 1.
- Combined oral contraceptive pills can also be used in specific doses as emergency contraception, although they are less effective than ulipristal acetate and levonorgestrel, and are associated with more frequent side effects such as nausea and vomiting 1.
Effectiveness and Side Effects
These methods work primarily by delaying or preventing ovulation, though copper IUDs may also prevent implantation.
- Emergency contraception is most effective when used as soon as possible after unprotected sex, with the copper IUD being the most effective option, followed by ulipristal acetate and levonorgestrel 1.
- They do not terminate existing pregnancies and may be less effective for women weighing over 165 pounds, especially with levonorgestrel formulations 1.
- Side effects are generally mild and include nausea, headache, fatigue, and temporary menstrual irregularities.
Recommendations
The copper IUD is the recommended emergency contraception option due to its high effectiveness and ability to provide ongoing contraception, as stated in the U.S. Selected Practice Recommendations for Contraceptive Use, 2013 1. Emergency contraception should not be used as regular birth control due to lower effectiveness than ongoing methods. Instead, it should be used as a backup option in case of unprotected sex or contraceptive failure. Advance provision of emergency contraceptive pills, such as ulipristal acetate and levonorgestrel, is also supported by the CDC to reduce unintended pregnancy risk 1.
From the FDA Drug Label
Ellais a prescription emergency contraceptive that reduces your chance of becoming pregnant if your birth control fails or you have unprotected sex. Ellais thought to work for emergency contraception primarily by stopping or delaying the release of an egg from the ovary. The emergency contraception is ella (ulipristal acetate), a prescription medication that works by stopping or delaying the release of an egg from the ovary, and is used to prevent pregnancy after unprotected sex or contraceptive failure 2.
- Key points:
- ella is for emergency use only, not for regular birth control
- It should be taken as soon as possible within 5 days (120 hours) after unprotected sex or contraceptive failure
- It is not intended to protect against HIV infection or other sexually transmitted diseases/infections 2
From the Research
Types of Emergency Contraception
- Levonorgestrel (LNG-EC) 3, 4, 5, 6
- Ulipristal acetate (UPA) 3, 5
- Copper intrauterine device (IUD) 3, 4, 7, 5
- Combined estrogen and progestin pills 4, 7
How Emergency Contraception Works
- Delay of ovulation 5, 6
- Possible effect on sperm migration in the female reproductive tract 6
- Possible effect on fertilization 6
Efficacy of Emergency Contraception
- Levonorgestrel: prevents around 50% of expected pregnancies when used within 72 hours of intercourse 3, prevents about 80% of pregnancies when used as a single 1.5-mg dose or two 0.75-mg doses taken 12 hours apart 6
- Ulipristal acetate: prevents almost two thirds of pregnancies 3, more efficacious in pregnancy prevention than levonorgestrel, especially when taken later than 72 hours postcoitus 5
- Copper IUD: prevents over 95% of pregnancies 3, the most effective method of emergency contraception 5
Accessibility and Usage
- Improved accessibility of emergency contraception has led to increased use, but it does not appear to have had any public health benefit in reducing unintended pregnancy rates 3
- Advance provision of emergency contraception does not appear to decrease rates of unintended pregnancy compared to routine pharmacy access 4, 6
- Women who are counseled by their clinician about emergency contraception are more likely to use it 4