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Quick Facts

Intrauterine Devices

By The Manual's Editorial Staff, ,

What are intrauterine devices (IUDs)?

An intrauterine device (IUD) is a type of birth control. It is a small T-shaped plastic device that a doctor can place in your uterus to prevent pregnancy. Your uterus is the organ where babies live and grow before they’re born.

IUDs are put into your uterus through your vagina (the muscular tube that connects your uterus to the outside of your body, also called the birth canal). A plastic string is attached to the IUD. The string lets you make sure the IUD is still in place and helps your doctor remove it.

  • IUDs work very well to prevent pregnancy and last between 3 and 10 years

  • IUDs don't have body-wide effects

  • A doctor must put in and remove your IUD

  • You can get pregnant immediately after removing an IUD

  • An IUD may change how much you bleed or cramp during your period

  • If put in within 5 days of sex, a copper IUD works as emergency contraception

Understanding Intrauterine Devices

Intrauterine devices (IUDs) are inserted by a doctor into a woman’s uterus through the vagina. IUDs are made of molded plastic. Two types of IUDs release a progestin called levonorgestrel. The other type is T-shaped and has a copper wire wrapped around the base and on the arms of the T. A plastic string is attached to the IUD. The string enables a woman to make sure the device is still in place and a doctor to easily remove it.

How do IUDs prevent pregnancy?

IUDs prevent pregnancy by:

  • Killing sperm

  • Preventing sperm from getting to your egg

  • If an egg does get fertilized, the IUD may also keep the fertilized egg from attaching to your uterus

  • IUDs don't remove a fertilized egg that has already attached to your uterus

What types of IUDs can I use?

There are 2 kinds of IUDs:

  • IUDs with hormones

  • IUDS containing copper (copper wire is wrapped around the device) instead of hormones

An IUD with hormones:

  • Lasts 3 or 5 years

  • About 1 in 100 women get pregnant while using it

  • Releases a hormone called progestin

  • May cause you not to bleed or bleed only a little during your period

A copper IUD:

  • Doesn't give off hormones

  • Lasts 10 years

  • About 2 in 100 women get pregnant while using it

  • Can cause more bleeding and cramps during your period

Who can use IUDs?

Most women can use IUDs, including teenagers and women who haven’t had children.

You shouldn't have an IUD put in if you have:

  • An infection in your pelvis, such as an STD (sexually transmitted disease) or pelvic inflammatory disease

  • An unusually shaped uterus

  • Unexplained bleeding from your vagina

  • Cancer of your cervix (lower part of your uterus) or the lining of your uterus

  • Breast cancer or an allergy to progestin (for hormonal IUDs)

  • Wilson disease (a disease that causes a buildup of copper in your body) or an allergy to copper (for copper IUDs)

You shouldn't have an IUD put in if you're pregnant.

What are problems with IUDs?

Problems that may happen with an IUD include:

  • IUD coming out by itself during the first year (more likely in women who are young or haven’t had children)

  • IUD punching a hole in your uterus when it’s put in (rare)

  • Increased chance of infection in your pelvis in the first month you have an IUD

  • Increased bleeding and cramps during your period (copper IUD only)

What are benefits of IUDs?

  • Birth control that works very well to prevent pregnancy

  • Lower chance of getting cancer in your uterus

  • Lighter bleeding during your period (hormonal IUDs only)

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