Intrauterine Device (IUD)

What is an IUD?

The letters "IUD" stand for "intrauterine device." IUDs are small, "T-shaped" contraceptive devices made of flexible plastic. IUDs are inserted by a medical provider into the uterus.

There are two brands of IUDs available on the US market, the ParaGard copper-T, and the Mirena. The IUD remains a medically safe method for many women and is the reversible contraceptive method used by more women across the globe.

How does it work to prevent pregnancy?

IUDs work by preventing an egg from being fertilized, although scientists are not exactly sure how this happens. Theories about this process include:

  • It affects the way the sperm or egg moves
  • Substances released by the IUD immobilize sperm
  • It moves the egg through the fallopian tube too fast to be fertilized.

The copper in the ParaGard adds to the effectiveness of the IUD in other ways. It affects the lining of the uterus by not allowing an egg to implant and it stimulates the production of prostaglandins, chemicals that affect the hormones needed to support a pregnancy. The ParaGard may be left in place for up to 12 years.

The Mirena IUD prevents pregnancy by releasing the hormone progestin, which suppresses ovulation (no egg is released). Progestin also thickens a woman’s cervical mucus, blocking sperm from entering the uterus. The Mirena IUD is effective for 5 years.

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How effective is the IUD in preventing pregnancy and STIs?

The IUD is one of the most effective methods of contraception available. Less than 1 in 100 women will get pregnant each year using the Mirena or ParaGard IUD.  However, IUDs do not offer any protection against sexually transmitted infections (STIs).

What are the benefits of using an IUD?

  • The ParaGard IUD does not change a woman's hormone levels.
  • The Mirena IUD may reduce period cramps and make your period lighter. For some women, periods stop altogether.
  • There is a quick return to fertility once the IUD is removed.
  • IUDs can be used during breastfeeding.

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Who should not use an IUD?

The IUD is not recommended in the following circumstances:

  • Active pelvic infection or a history of pelvic inflammatory disease (PID)
  • Multiple sexual partners
  • Cervicitis (inflamed or infected cervix)
  • Bleeding disorders
  • History of ectopic pregnancy (pregnancy developed in fallopian tubes)
  • Impaired response to infection (AIDS, diabetes, steroid treatment, etc.)
  • Severe cramping with periods
  • Heavy menstrual flow
  • Allergy to copper (for ParaGard)
  • Anemia
  • History of a sexually transmitted infection
  • Previous pelvic surgery

Where can I go to get an IUD and how much does it cost?

Health Services does not currently have the IUD available. However, medical providers here are willing to talk with students who are interested in an IUD and can offer referrals. Brown students can make an appointment by calling 401.863-3953.

Links you can use:

For more information about IUDs you can visit:

Planned Parenthood

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