1. Birth Control Slideshow Pictures
2. Slideshow: What's Causing Your Pelvic Pain?
3. Women's Health Slideshow: Embarrassing Beauty Q&A

Medical Author:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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In this Article

• Introduction to birth control
• What are intrauterine devices (IUDs)?
• What are the types of intrauterine devices (IUDs)?
• How does an intrauterine device (IUD) work?
• What are the advantages of an intrauterine device (IUD)?
• What are the side effects of an intrauterine device (IUD)?
• How is an IUD removed?
• What are the risks and complications of intrauterine devices (IUDs)?
• Find a local Obstetrician-Gynecologist in your town
• IUD Index

What are the types of intrauterine devices (IUDs)?

Intrauterine devices (IUDs) come in two different types: 1) copper-releasing, or 2) progesterone-releasing.

1. The TCu380A (Paragard) is a copper-containing IUD. It releases copper from a copper wire that is wrapped around the base. The released copper contributes to an inflammatory reaction in the uterus that helps prevent fertilization of the egg. It is approved to remain in place for up to 10 years.
   
   
2. Levonorgestrel-releasing IUD (Mirena): This form of IUD releases a progestin hormone from the vertical part of the T. Progestin acts to thicken cervical mucus, creating a barrier to sperm, as well as renders the lining of the uterus inhospitable to implantation of a pregnancy. This form of IUD is approved for up to five years of use.

How does an intrauterine device (IUD) work?

It is not fully understood how IUDs work. They are thought to prevent conception by causing a brief localized inflammation that begins about 24 hours after insertion. This causes an inflammatory reaction inside the uterus that attracts white blood cells. The white blood cells produce substances that are toxic or poisonous to sperm. The progesterone-releasing IUDs also cause a subtle change in the endometrial environment that impairs the implantation of the egg in the uterine wall. This type of IUD also alters the cervical mucus, which, in turn, inhibits sperm from passing through the cervix.

IUDs are only available by prescription and must be properly inserted by a health care professional. A pelvic exam is required to insert an IUD. The IUD is usually inserted into the uterus during a woman's menstrual period although it can be done at any time during her monthly cycle as long as she is not pregnant.

The woman must check her IUD every month to be sure that the IUD is still in place. Sometimes, the uterus expels (pushes out) the IUD. The spontaneous expulsion rate has been reported to be as high as 10% during the first year of use. Expulsions may not cause any specific symptoms and can be overlooked. In addition to the woman checking the IUD, the device must also be checked periodically by a health care professional.