Emergency Contraception Safety: Effectiveness and Risks

Emergency contraception is a way to prevent pregnancy after having unprotected sex, meaning sex without birth control or with birth control that didn't work. The two main types of emergency contraception are emergency contraceptive pills (ECPs) and the copper intrauterine device (IUD).

As with any medical treatment, you may wonder if emergency contraception is safe. Read on to learn about the safety of both emergency contraception methods.

ECPs, which are also called 'morning-after pills,' are hormone pills. They use high levels of the hormones found in birth control pills to prevent pregnancy. They must be taken within three or five days of unprotected sex, depending on the product.

Brands available in the United States contain the hormone levonorgestrel or the hormone ulipristal.

Levonorgestrel ECPs include:

• Plan B One-Step
• levonorgestrel (generic Plan B)
• Next Choice One Dose
• Athentia Next
• EContra EZ
• Fallback Solo
• Her Style
• My Way
• Opcicon One-Step
• React

The ulipristal ECP is:

• ella

All ECPs are thought to be very safe.

'These are extraordinarily safe drugs,' says Dr. James Trussell, faculty associate at Princeton University and researcher in the area of reproductive health. Dr. Trussell has actively promoted making emergency contraception more widely available.

'No deaths have been linked to using emergency contraceptive pills. And the benefits of being able to prevent pregnancy after sex outweigh any possible risks of taking the pills.'

The copper IUD is a small, hormone-free, T-shaped device that a doctor places in your uterus. It can serve as both emergency contraception and long-term pregnancy protection. To act as emergency contraception, it must be placed within five days of unprotected sex. Your doctor can remove the IUD after your next period, or you can leave it in place to use as long-term birth control for up to 10 years.

The copper IUD is thought to be very safe. But in rare cases, it can cause serious problems. For example, an IUD could pierce the wall of the uterus while it's being inserted. Also, the copper IUD slightly raises your risk of pelvic inflammatory disease in the first three weeks of use.

Again, these risks are rare. Your doctor can help you decide if the benefit of placing a copper IUD outweighs the potential risks.

Learn more: Intrauterine devices »

Women who should avoid these options

Some women should avoid using the copper IUD. For example, women who are pregnant shouldn't use it because it raises the risk of infection. The copper IUD should also be avoided by women who have:

• distortion of the uterus
• pelvic inflammatory disease
• endometritis after pregnancy or miscarriage
• cancer of the uterus
• cervical cancer
• genital bleeding for unknown reasons
• Wilson's disease
• infection of the cervix
• an older IUD that has not been removed

Certain women should also avoid using ECPs, including those who are allergic to any of the ingredients or those who take certain medications that may make ECPs less effective, such as barbiturates and St. John's wort. If you're breastfeeding, you should not use ella. However, levonorgestrel ECPs are safe for use while breastfeeding.

ECPs and pregnancy

ECPs are meant to prevent pregnancy, not end one. The effects of ella on a pregnancy aren't known, so for safety, you shouldn't use it if you're already pregnant. ECPs that contain levonorgestrel don't work during pregnancy and won't affect a pregnancy.

Effects of weight on ECP effectiveness

All emergency contraceptive pills, regardless of type, appear to be much less effective for obese women. In clinical trials of women using ECPs, women with a body mass index of 30 or greater became pregnant more than three times as often as non-obese women. Ulipristal acetate (ella) may be more effective for overweight or obese women than ECPs that contain levonorgestrel.

That said, the best choice of emergency contraception for women who are overweight or obese is the copper IUD. The effectiveness of the copper IUD used as emergency contraception is greater than 99% for women of any weight.

Risk with cardiovascular problems

Some women's doctors may have told them not to use birth control pills because they are at risk of stroke, heart disease, blood clots, or other cardiovascular problems. However, using an ECP is different from using birth control pills. One-time use of emergency contraceptive pills does not carry the same risks as taking oral contraceptives every day.

If your healthcare provider has said you should absolutely avoid estrogen, you can probably still use one of the ECPs or the copper IUD. However, you should talk with your doctor about which contraception options are safe for you.

Birth control pills as emergency contraception

Regular birth control pills that contain levonorgestrel plus an estrogen may be used as emergency contraception. For this method, you would need to take a certain number of these pills shortly after you have unprotected sex. Be sure to talk with your doctor to get their approval and specific instructions before using this method.

Read more: Safe sex basics for women »

Emergency contraception comes as two types of hormonal pills, available under various brand names, and as a nonhormonal intrauterine device (IUD). Women with certain health conditions may not be able to use these methods. However, emergency contraceptives are generally safe for most women.

If you still have questions about emergency contraception, talk to your doctor. Questions you may want to ask could include:

• What type of emergency contraception do you think would work best for me?
• Do I have any health conditions that would make emergency contraception unsafe for me?
• Am I taking any drugs that might interact with ECPs?
• What kind of long-term birth control would you suggest for me?