January 27, 2023

These are methods and medications used after sex that prevent pregnancy.

Emergency contraception reduces the chances of getting pregnant after unprotected sexual intercourse, which means without using effective birth control.

Emergency contraception can be useful if a condom breaks, if you’ve used your birth control incorrectly or aren’t using any method to prevent pregnancy but do not want to become pregnant. It can also be used in cases of sexual assault. 

You may also want to consider emergency contraception if you have sex within weeks or months of giving birth and you have not started using regular birth control since delivering.

How does emergency contraception work?

“There are multiple options for emergency contraception, which differ by how you use them and how effective they are,” said Dr. Elise Boos, an OB-GYN with Vanderbilt Women’s Health. “Emergency contraception works best the sooner it’s used after sex. These methods are not intended to replace contraception; they are intended to be used when you’ve had unprotected sex and want to reduce the risk of pregnancy,” said Dr. Boos.

Emergency contraception does not cause an abortion. It prevents pregnancy from occurring in the first place, Dr. Boos said.

IUDs as emergency contraception and for long-term use

IUDs are the most effective method of emergency contraception. The copper IUD has historically been the go-to method for emergency contraception, but today health-care providers know that hormone IUDs are likely to work just as well as the copper IUDs. If you get an IUD for emergency contraception, it can be left in place as your long-term birth control method. The sooner an IUD is placed after unprotected sex, the better. 

Emergency contraception pills

There are two pill options for emergency contraception, also known as “morning-after pills”: Plan B and Ella. 

Plan B is a progesterone-based emergency contraceptive. It’s a one-time pill available over the counter without a prescription. Plan B is most effective if taken within 72 hours of unprotected sex. It is safe to use if breastfeeding, Dr. Boos said.

Ella (also known as ulipristal acetate) is also a one-time pill but is more effective than Plan B. It requires a prescription. Ella can be taken within five days of unprotected sex and is the preferred pill method for those who are overweight. While it is safe to take while breastfeeding, it is recommended that you pump and discard your milk for 24 hours after taking Ella, because the medicine is excreted in breastmilk. 

Take a pregnancy test anyway

Someone using an emergency contraceptive pill should also take a pregnancy test two to three weeks later, Dr. Boos said, to be sure they have avoided pregnancy. It’s possible that the menstrual cycle can run early or late, depending on the effect the pill may have. 

If you are using a hormonal birth control method and you take Plan B, you’ll need to continue your birth control but use a back-up method for seven days after taking Plan B. 

If you use hormonal birth control and take Ella, you’ll want to delay use of the birth control method for five days, then use a back-up method until your next period, Dr. Boos said. Using Ella and hormonal birth control at the same time will reduce the effectiveness of both.

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