Health Information and Tools > Sexual and Reproductive Health > Birth Control >  Intrauterine Device (IUS, IUD, or IUS)
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Sexual and Reproductive Health

Intrauterine Contraceptives (IUC, IUD, or IUS)

What are intrauterine contraceptives (IUC)?


An IUC is a small, soft, T-shaped device with a nylon string attached to it. It is put in the uterus by a health care provider to help prevent pregnancy.

The IUC prevents pregnancy by stopping the egg and sperm from meeting. A woman can’t get pregnant if the sperm and egg don’t meet.

There are 2 types of IUC (copper and hormonal). They work in different ways to help prevent pregnancy.

This intrauterine device (IUD) has a copper wire wrapped around it. The IUD:

  • Changes the lining of the uterus so that if an egg is fertilized, it’s less likely to attach to it
  • Slows the sperm movement, so it is harder to get to the egg

Depending on the type of copper IUD, it can help prevent pregnancy for up to 10 years.

This intrauterine system (IUS) has a hormone (progestinl) wrapped around it that is slowly released into the uterus. The IUS:

  • thickens the mucous in the cervix, so it is harder for the sperm to get to the egg
  • thins the lining of the uterus, which makes it less likely that a fertilized egg will attach to it slows the sperm movement, so it is harder to get to the egg
  • may stop the ovaries from releasing an egg

The IUS can help prevent pregnancy for 3 to 5 years.

How well do IUC work?

  • There’s about an 85% chance of getting pregnant after one year of having unprotected sex.
  • The copper IUD is 99.2% effective in preventing pregnancy.
  • The hormonal IUS is more than 99% effective in preventing pregnancy.
  • An IUD doesn’t protect you from sexually transmitted infections (STIs) and HIV.
  • Use a condom every time you have sex (vaginal, oral, anal) to lower your risk of STIs and HIV.

How do I start using IUC?

Before you get an IUC, get checked for STIs or other vaginal infections.

You need a prescription. The IUC is put in (inserted) by a health care provider. Check the strings every month to see if your IUC is still in the right place. The health care provider will teach you how to feel for the strings when your IUC is inserted.

The copper IUD protects you from pregnancy as soon as it is inserted.

If your hormonal IUS is inserted on:

  • day 1 to 7 of your period, it works right away to prevent pregnancy
  • any other day, you need an extra form of birth control (e.g., condoms, abstinence) for 7 days

What are the benefits of an IUC?

  • IUDs are cost effective, convenient and private.
  • IUDs can be put in right away after an abortion, miscarriage, delivery or if you’re breastfeeding.
  • The hormonal IUD might help improve symptoms for people who have endometriosis and adenmyosis.
  • The copper IUD can be used as emergency contraception (EC) up to 7 days after unprotected sex or contraceptive failure.
  • An IUC can help prevent pregnancy for 3 to 10 years (depending on the type).
  • If you want to get pregnant, your healthcare provider can take out your IUC at any time.
  • If you can’t use birth control with estrogen, you can use an IUC.
  • The copper IUD may lower your risk of cancer of the uterus.
  • The hormonal IUS may make your periods lighter or you might even stop having periods. It might also make your period cramps better.

How will an IUC affect my period?

The copper IUD may cause:

  • more bleeding and cramping with your period (this should get better over time)
  • light bleeding or spotting between periods

If you use the hormonal IUS, you may have:

  • less bleeding and cramping
  • light bleeding or spotting between periods in the first few weeks to months
  • much lighter periods over time
  • no periods, depending on the type used.After 6 months, 2.7%-44% of people stop having a period. The higher the dose of hormones, the more likely the period will stop. This is safe.

What are the side effects of an IUC?

With the hormonal IUS, there is a chance (especially in the first few months) that you may have:

  • headaches
  • tender breasts
  • acne
  • mood changes
  • nausea

What are the disadvantages of having an IUC?

There is a 2 to 10% chance of the IUC falling out. This happens most often in the first year especially in the first 3 months. This risk is greater if:

  • the IUC was inserted right after you had a baby
  • you have had an IUC fall out before
  • you have never been pregnant
  • heavy periods
  • lots of uterine cramping
  • fibroids or your uterus is a different shape than normal

It is rare to get pregnant while using an IUC. If you do get pregnant with an IUC, there is a higher risk of:

  • a pregnancy outside the uterus (ectopic pregnancy)
  • miscarriage

There’s a small risk (less than 5%) of getting an infection called pelvic inflammatory disease (PID) after having an IUD put in. The risk is higher:

  • in the first month after insertion
  • if you have an STI. STI and not the IUD itself is responsible for PID.

PID in the uterus and fallopian tubes might cause scarring in the reproductive organs, which might make it harder to get pregnant later.

In rare cases, an IUC can make a hole in the wall of the uterus when it is being inserted. If this happens, you may need a minor surgery to take it out. The risk is higher if you’ve recently had a baby or if you’re breastfeeding.

I’m thinking of getting an IUC. When do I need to contact my healthcare provider?

If you are thinking of getting an IUC, tell your healthcare provider if you:

  • are pregnant or think you might be
  • have an STI
  • have ever had PID
  • have an allergy to copper
  • have breast, cervix, or uterine cancer
  • have irregular vaginal bleeding or don’t have your period
  • have fibroids or your uterus is a different shape than normal

If I have an IUC, when do I need to contact my healthcare provider?

Contact your healthcare provider if you have an IUC and you:

  • think you are pregnant
  • have unscheduled and persistent vaginal bleeding
  • have lots of abdominal cramping
  • can’t find your strings or the strings are longer or shorter
  • think you have been exposed to an STI
  • have a copper IUD and miss your period
  • have a sudden change in periods
  • have pelvic pain or vaginal discharge with or without a fever or chills
  • have pain with sex or your partner can feel your strings during sex
  • have any questions or other problems with your IUC
  • want to remove your IUC

Call your health care provider if you can’t find your strings or you think your IUD is falling out (e.g., you can feel the hard plastic part). If this happens, you may not be protected from pregnancy. If you’ve had unprotected sex in the last 5 days, get emergency contraception as soon as possible.

Did You Know

  • You have the right to make the decision to have sex or not.
  • Plan ahead and decide to protect yourself to lower your risk of pregnancy, STIs, and HIV.
  • It is important to talk with your partner about how you can protect each other.
  • You can get pregnant as soon as you have your IUC removed.
  • You can contact your healthcare provider anytime to remove your IUC.
  • An IUC can be expensive, but the longer you use it, the more cost-effective it is.
  • Many sexual health clinics offer some types of birth control for no cost for those who qualify.

For More Information

  • Health Link – Health Advice 24/7: 811

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