Copper IUD

Named after the contraceptive substance released, the copper IUD is highly effective at preventing pregnancy.

Intrauterine devices (IUDs) are a reversible method of birth control. The copper IUD (ParaGard) is one of two IUDs available by prescription in the United States. The other IUD is a hormonal version (Mirena).

The copper IUD is a T-shaped plastic frame with two threads attached. It's inserted into the uterus to prevent pregnancy. Once in place, it inhibits fertilization, as the IUD impedes the sperm's journey to the fallopian tubes. If fertilization occurs, the device prevents the embryo from attaching to the uterine wall. ParaGard also slowly releases copper, which inactivates the sperm in the cervical mucus.

Effectiveness rate. The effectiveness rate for the copper IUD is between 99.2 percent and 99.4 percent, meaning that six to eight women out of 1,000 who use it for one year will get pregnant. The copper IUD may remain in place for up to 10 years.

Side effects and health risks. Common side effects associated with the copper IUD are increased vaginal bleeding and menstrual pain. Taking nonsteroidal anti-inflammatory drugs (Advil, Motrin, others) helps with these symptoms. Some women may also experience a pelvic infection within the first three weeks of placement, as the insertion process may introduce bacteria into the uterus. Your doctor may prescribe antibiotics before insertion to reduce the risk of such infections. The copper IUD doesn't protect against STDs. IUDs also carry a risk of spontaneous expulsion — which leaves you unprotected against pregnancy — or piercing (perforation) of the uterine wall during insertion.

How to use the copper IUD. If you decide on the copper IUD, your doctor will insert the device and give you information on its use. When ParaGard needs to be removed, your doctor gently withdraws it by pulling on the IUD string. In rare instances the strings on the device may break, making IUD removal a more complicated procedure. After removal, normal fertility returns promptly.

Cost and availability. The copper IUD costs $200 to $300 every ten years plus the cost of an office visit for insertion and a follow-up appointment.