Overview

The intrauterine device (IUD) is used to prevent pregnancy. It's a small, plastic, T-shaped device. Your doctor places the IUD in your uterus.

There are two types of IUDs. Hormonal IUDs release a type of progestin to prevent pregnancy for 5 years. Copper IUDs do not use hormones and prevent pregnancy for 10 years. In some cases an IUD can be used longer.^{footnote 1} Talk to your doctor about how long you can use your IUD. Once you have an IUD, you don't have to do anything else to prevent pregnancy.

The IUD usually stays in the uterus until your doctor removes it.

How well does it work?

The IUD is a highly effective method of birth control.

• IUDs are more than 99% effective for preventing pregnancy.^{footnote 1} That means fewer than 1 out of 100 people who use an IUD as directed will have an unplanned pregnancy.
• Most pregnancies that occur with IUD use happen because the IUD is pushed out of (expelled from) the uterus unnoticed. IUDs are most likely to come out in the first few months of IUD use, after being inserted just after childbirth, or in people who have not had a baby.

What are the risks?

Using an IUD is safe and rarely causes problems. But some possible problems include:

• Menstrual problems. The copper IUD may increase menstrual bleeding or cramps. You may also have spotting between periods.
• Perforation. This means the IUD passes through the uterine wall. Perforation is rare, but when it occurs, it's almost always during insertion. The uterus usually heals on its own after a perforation.
• Expulsion. This means the IUD moves out of place. If expulsion occurs, it usually happens in the first few months of use. Expulsion is more likely when the IUD is inserted right after childbirth or in a person who has never been pregnant. If you think your IUD has been expelled, use a backup birth control method until you can see a health care provider.
• Unplanned pregnancy. Rarely, an unplanned pregnancy happens, especially if the IUD moves out of place. If an unintended pregnancy occurs, the IUD needs to be removed right away.