Intrauterine Device (IUD)
Effectiveness in Preventing Pregnancy
- Of 100 women using IUDs for a year, less than one may become pregnant.
- IUDs are better at preventing pregnancy than condoms, the pill, patch, ring, and shot.
What is an IUD?
An IUD is a small T-shaped device that is placed in the uterus by a healthcare provider. It sits inside the uterus, and the cervix keeps it in place. Once it is in, you cannot feel it. There are two types of IUDs: the non-hormonal–copper T IUD and the hormonal–levonorgestrel IUD.
Non-hormonal Copper T IUD
- The non-hormonal copper T IUD contains no hormones and is made with copper and plastic. The copper prevents pregnancy by acting as a spermicide (a substance that kills sperm), preventing sperm from reaching and fertilizing an egg.
- It starts preventing pregnancy as soon as it is placed. In fact, the copper T IUD is an extremely effective method of emergency contraception when it is placed within five days of unprotected intercourse.
- Once in place, it is effective for up to 10 years.
Hormonal Intrauterine Device (IUD)
- Hormonal IUDs contain the progestin levonorgestrel, which is a hormone. Hormones are chemicals that control how different parts of your body work. The progestin causes cervical mucus to thicken and the lining of the uterus to thin. This keeps the sperm from reaching and fertilizing an egg.
- It may take a week for the hormonal IUD to begin working, so ask your healthcare provider if you should wait to have sex or use a back-up birth control method (such as a condom) in the meantime.
- It is effective for 3 to 5 years, depending on the type.
- It may also be called an intrauterine system or an intrauterine contraceptive.
How do I use it?
Your healthcare provider will place an IUD through your vagina and cervix and into your uterus. The IUD has strings that can be felt in the back of the vagina, but they do not stick out of the vagina (like a tampon string). Your healthcare provider will cut the strings to an appropriate length once the IUD is placed.
If you are interested, your healthcare provider can teach you how to check your IUD strings on your own between visits to ensure that the IUD is still in place. Very rarely, an IUD may come out of the uterus on its own. If the IUD comes out, do not try to put it back yourself. Call your healthcare provider to insert another one for you.
It is not uncommon for women to have some mild discomfort, cramping, or spotting after the IUD is first placed. In most cases, symptoms become milder or go away in a few weeks or months.
Some women have heavier periods when they use the copper T IUD—particularly in the first three months. Speak with your healthcare provider about using over-the-counter medications that might help make your period lighter.
Ask your healthcare provider about the types of symptoms you should expect. Uncommon risks are pelvic infection after placement or perforation (poking through the side) of the uterus.
How do I get it?
An IUD can only be placed by a healthcare provider. Most family planning clinics offer IUDs.
Advantages of an IUD
- IUDs are safe and effective in preventing pregnancy—even more effective than other methods of reversible birth control.
- Along with implants, IUDs are one of the most cost-effective, long-acting reversible methods of birth control.
- It works for 3 to 10 years, depending on the type.
- There is nothing you have to remember to do.
- It is private. It is your choice if your partner knows about it.
- It can be removed at any time by a healthcare provider.
- Once an IUD is removed, your ability to get pregnant will immediately go back to whatever is normal for you.
- The copper T IUD can also be used as emergency contraception to prevent pregnancy if inserted within five days after unprotected sex.
Drawbacks of an IUD
- An IUD requires a clinic visit for placement.
- It does not protect against sexually transmitted diseases (STDs), including HIV. Always use a condom to reduce the risk of STDs.
- Shortly after placement, women may experience side effects like cramping and irregular bleeding.
- Although rare, some women develop pelvic infections, most often within the first three weeks after placement.
- Although rare, IUDs may come out of the uterus.
Did You Know?
Condoms add extra protection against pregnancies and STDs when used with other birth control methods.
Content last reviewed on October 11, 2017