Intrauterine System (IUS)

What is an Intrauterine System?

An intrauterine system is similar to the IUD (Intrauterine Device) in many ways but is a hormonal method of contraception. It is a small T-shaped piece of plastic containing the hormone progestin that is inserted by a healthcare practitioner into the uterus to prevent pregnancy. Progestin, which is also used in the birth control pill, reduces the risk of pregnancy by thinning the lining of the uterus so that a pregnancy cannot grow in it. Progestin also thickens the mucus in your cervix making it more difficult for sperm to get to the uterus. Attached to the IUS are two threads that hang down an inch past the cervix (the opening to the uterus) and into the top of the vagina.

How does an IUS work?

An IUS must be inserted by a doctor. The IUS is inserted into your uterus and the strings are cut just below your cervix. Check the strings after each period. If you can feel the plastic part or the strings are missing, use another form of birth control such as condoms and spermicide until you can see your doctor. Never attempt to remove the IUS yourself. Period-like cramping and spotting is common within the first 3 months of insertion.

Where can you get an IUS?

A prescription is required from a health care provider. You can have an IUS inserted at some walk-in clinics. If you have a family doctor, you can ask them if they have inserted many IUS’s and if they will insert an IUS for you.

How much does an IUS cost?

Approximately $350-$450. It is covered by most private drug plans.

How effective is an IUS?

The IUS is approximately 99% effective in preventing pregnancy.

Does an IUS reduce the risk of STIs?

No. The IUS does not reduce the risk of sexually transmitted infections.

Reasons someone might choose this method of birth control

  • Very effective in preventing pregnancy
  • It decreases cramping and greatly reduces the flow of the menstrual cycle. Many people who use the IUS end up stopping their periods while on it.

Reasons someone might not choose this method of birth control

  • It has a high initial cost.
  • In rare (6.7%) cases, the IUS can fall out.
  • If you are uncomfortable using hormones or are sensitive to hormones this may not be the best method for you

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