An IUD is a small T-shaped device that is put in the uterus by a healthcare provider. It sits in your uterus and your cervix keeps it in place. Once it’s in, you can’t feel it. Two types are available:

• The Copper T IUD is made with copper and plastic. It prevents pregnancy by blocking sperm from reaching or fertilizing the egg, and may prevent implantation.

• The hormonal intrauterine system contains the hormone, progestin. 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 the egg.

An IUD is placed through your vagina and cervix and into your uterus by a health care provider. The Copper IUD will prevent pregnancy right away. It may take a week for the hormonal intrauterine system to begin working, so ask if you need to use a back-up birth control method (like a condom) in the meantime.

Once in place, copper IUDs are effective for up to 10 years (depending on the type of copper IUD). The hormonal intrauterine system will last for up to five years. But any IUD can be taken out at any time. Just ask your healthcare provider.

It is common for women to have some mild discomfort, cramping, and spotting after the IUD is first inserted. In most cases, this will become milder or go away in a few weeks or months. Ask your health care provider about what types of symptoms you should expect.

Your health care provider may also ask you to check your IUD strings on your own between visits to make sure they can be felt in your vagina. They will tell you more about how to do this.

Very rarely, an IUD may come out of your uterus on its own. This is more common in women who have never had a baby. If the IUD comes out, do not try to put it back yourself. Call your healthcare provider and they will insert another one for you.

Of 100 women who use an IUD each year, less than one may become pregnant. IUDs are better at preventing pregnancy than condoms, the pill, the patch, the ring, and the injectable contraceptive.

• Safe and effective in preventing pregnancy, even more effective than other methods of reversible birth control 

• Along with implants, IUDs are the most cost-effective reversible method of birth control 

• IUDs work for many years.

• IUDs can be taken out at any time if you want to get pregnant or are unhappy with it 

• The Copper T IUD can also be used as emergency contraception to prevent pregnancy if inserted within five days after unprotected sex 

• There is nothing you have to remember, which can be great for people who have a hard time remembering or don’t want to remember to use other methods like the pill, patch, or ring. 

• Your partner doesn’t have to know about it or do anything different.

• Requires a clinic visit for insertion

• Provides no protection against sexually transmitted infections (STIs), including HIV

• May cause side effects like cramping and irregular bleeding

• While not common, a few women may develop pelvic infections with an IUD, most often within three weeks after insertion.

• Rarely, IUDs will come out of the uterus.

By itself, the IUD does not cause PID. Gonorrhea and chlamydia are the primary direct causes of PID. IUD insertion when a woman has gonorrhea or chlamydia may lead to PID, however. This does not happen often. When it does, it is most likely to occur in the first 20 days after IUD insertion. It has been estimated that, in a group of clients where STIs are common and screening questions identify half the STI cases, there might be 1 case of PID in every 666 IUD insertions (or less than 2 per 1,000).

Yes. There is no minimum or maximum age limit. An IUD should be removed after menopause has occurred—within 12 months after her last monthly bleeding.

No. If a woman develops a new STI after her IUD has been inserted, she is not especially at risk of developing PID because of the IUD. She can continue to use the IUD while she is being treated for the STI. Removing the IUD has no benefit and may leave her at risk of unwanted pregnancy. Counsel her on condom use and other strategies to avoid STIs in the future.

No. A woman can become pregnant once the IUD is removed just as quickly as a woman who has never used an IUD, although fertility decreases as women get older. Good studies find no increased risk of infertility among women who have used IUDs, including young women and women with no children. Whether or not a woman has an IUD, however, if she develops PID and it is not treated, there is some chance that she will become infertile.

Yes. A woman who has not had children generally can use an IUD, but she should understand that the IUD is more likely to come out because her uterus may be smaller than the uterus of a woman who has given birth.

The IUD never travels to the heart, brain, or any other part of the body outside the abdomen. The IUD normally stays within the uterus like a seed within a shell. Rarely, the IUD may come through the wall of the uterus into the abdominal cavity. This is most often due to a mistake during insertion. If it is discovered within 6 weeks or so after insertion or if it is causing symptoms at any time, the IUD will need to be removed by laparoscopic or laparotomic surgery. Usually, however, the out-of-place IUD causes no problems and should be left where it is. The woman will need another contraceptive method.

No. This is not necessary, and it could be harmful. Removing the old IUD and immediately inserting a new IUD poses less risk of infection than 2 separate procedures. Also, a woman could become pregnant during a “rest period” before her new IUD is inserted.

No, usually not. Most recent research done where STIs are not common suggests that PID risk is low with or without antibiotics. When appropriate questions to screen for STI risk are used and IUD insertion is done with proper infection-prevention procedures (including the no-touch insertion technique), there is little risk of infection. Antibiotics may be considered, however, in areas where STIs are common and STI screening is limited.

No. For a woman having menstrual cycles, an IUD can be inserted at any time during her menstrual cycle if it is reasonably certain that she is not pregnant. Inserting the IUD during her monthly bleeding may be a good time because she is not likely to be pregnant, and insertion may be easier. It is not as easy to see signs of infection during monthly bleeding, however.

No. On the contrary, IUDs greatly reduce the risk of ectopic pregnancy. Ectopic pregnancies are rare among IUD users. The rate of ectopic pregnancy among women with IUDs is 12 per 10,000 women per year. The rate of ectopic pregnancy among women in the United States using no contraceptive method is 65 per 10,000 women per year.

On the rare occasions that the IUD fails and pregnancy occurs, 6 to 8 of every 100 of these pregnancies are ectopic. Thus, the great majority of pregnancies after IUD failure are not ectopic. Still, ectopic pregnancy can be life-threatening, and so a provider should be aware that ectopic pregnancy is possible if the IUD fails.