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What is an IUS?

  • An IUS is a small T-shaped piece of plastic that a health care provider inserts into a uterus to prevent pregnancy.
  • The IUS contains a hormone that slowly releases into the body.

How does an IUS work?

  • The IUS releases a hormone called progestin into the lining of the uterus.
  • This makes the cervical mucous thicker. This makes it harder for sperm to get into the uterus.
  • The hormone also thins the lining of the uterus, making it harder for a fertilized egg cell to attach to the uterus. Even if an egg cell is released and fertilized, it will not continue to grow if it is unable to attach to the uterine lining.
  • Some people do not ovulate when they are using an IUS.
  • It prevents pregnancy 99.9% of the time.
  • Depending on the type, an IUS lasts for 3-5 years. After 3 to 5 years, it can be removed and a new one put in if desired

Where can I get an IUS?

  • Talk to your healthcare provider.
  • Some community health clinics stock IUSs and can book an appointment for insertion.
  • Some healthcare providers may first give you a prescription to take to a pharmacy to buy the IUS. After purchase, return to your health care provider for insertion.
  • An IUS can be expensive. If cost is a problem, talk to your healthcare provider or your local community health clinic. There may be programs or supports available to reduce the cost/reduce financial barriers. Visit womenshealthclinic.org to learn more.

What can I expect at an IUS appointment?

  • The health care provider will examine you to check for pregnancy or any infections.
  • Next, they will do a pelvic exam (internal exam). They will insert a speculum (plastic or metal instrument) into your vagina to see your cervix and wash it with an antiseptic solution.
  • Next, they will insert an IUS into your uterus through the vagina. It may feel uncomfortable so you may want to ask for pain medication ahead of time.
  • The health care provider will leave the two plastic threads or strings that may hang down through the cervix into the vagina. These strings are very thin and do not hang outside the body.
  • You may want to check the strings from time to time to make sure the IUS is still in place.

Does an IUS protect me from STIs and HIV?

  • No, an IUS is only for pregnancy prevention.
  • Use safer sex supplies such as condoms and sex dams every time you have sex to reduce the risk of STIs (sexually transmitted infections) or HIV.
  • Getting an STI with an IUS increases the risk of Pelvic Inflammatory Disease (PID), which may damage reproductive organs, cause pain, and other serious problems. Test for STIs regularly and seek treatment if needed to prevent the risk of PID.

Are there any side effects?

You may feel some side effects. If you are concerned about the effects of hormones, consider an Intra-Uterine Device (IUD) instead. See SERC’s Fact Sheet on IUDs. If side effects are very uncomfortable or last longer than a few months, talk to your healthcare provider.

Minor side effects may include:

  • Cramping or discomfort during IUS insertion
  • Irregular bleeding for the first 3-6 months
  • No period after one year of use. Your period will return after the IUS removal

Serious side effects are rare, but can include:

  • Ectopic pregnancy (when an embryo attaches outside of the uterus)
  • Pelvic Inflammatory Disease (PID)

What if I want my IUS taken out?

  • A healthcare provider removes IUS. Do not try to take an IUS out by yourself.

What if my IUS comes out or I can’t feel the strings?

  • Call the health care provider who inserted the IUS as soon as possible. In the meantime, consider using another kind of birth control such as condoms.
  • If your IUS comes out and you think there may be a chance of pregnancy, see a healthcare provider or pharmacist for emergency contraception (ECP). ECP can work up to 5 days after unprotected sex but is most effective the sooner it is taken.

Where can I get more information?

  • From your health care provider, community health clinic, or public health nurse. If you need a regular healthcare provider, call the Family Doctor Finder at 204-786-7111.
  • From the Facts of Life (SERC): E-mail your questions to thefactsoflife@serc.mb.ca.
  • From a Teen Clinic if you are 21 or younger
  • Online at serc.mb.ca or our youth website, www.teentalk.ca

Sexuality Education Resource Centre 2023

To view or download a PDF version of this information, click here: STIs 2023

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