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Intrauterine Devices (IUDs)
The intrauterine device (IUD) is a small plastic T-shaped device that is inserted into the uterus. An IUD's contraceptive action begins as soon as the device is placed in the uterus and stops as soon as it is removed. IUDs have an effectiveness rate of close to 100%. They are also a reversible form of contraception. Once the device is removed, a woman regains her fertility.

Intrauterine Device Forms
Two types of intrauterine devices (IUDs) are available in the United States:
- Copper-Releasing (ParaGard). This type of IUD can remain in the uterus for up to 10 years. Copper ions released by the IUD are toxic to sperm, thus preventing fertilization.
- Progestin-Releasing (Mirena). This type of IUD can remain in the uterus for up to 5 years. Mirena is also known as a levonorgestrel-releasing intrauterine system, or LNG-IUS. Levonorgestrel impairs sperm motility and viability, thus preventing fertilization. LNG-IUS is long-acting, safe, very effective in preventing heavy bleeding, and helps reduce cramps. In fact, some doctors describe it as a nearly ideal contraceptive. In addition to being a contraceptive, it is approved as a treatment for heavy menstrual bleeding.
Inserting an Intrauterine Device
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Review Date: 09/28/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine,
Harvard Medical School; Physician, Massachusetts General Hospital.
Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M.,
Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)
