What's an intrauterine device?
The intrauterine device, or IUD, is a T-shaped plastic stick that's wrapped in copper or filled with a synthetic form of the hormone progesterone and inserted into your uterus. It's better than 99 percent effective in preventing pregnancy.
How does it work?
The copper IUD interferes with fertilization by keeping sperm away from the egg. If fertilization occurs, it will prevent the embryo from attaching to the uterus. The copper IUD also slowly releases the metal in the cervix which inactivates the sperm. The hormonal one works in the same way and also prevents the lining of the uterus from thickening, which makes it difficult for a fertilized egg to become implanted there.
Doesn't the IUD have a bad reputation?
It's making a comeback after falling out of favor in the United States during the 1970s. At that time, many women who used a particular kind of IUD called the Dalkon Shield developed pelvic inflammatory disease (PID), an infection that can lead to infertility and even death if left untreated. The Dalkon Shield is no longer on the market. Since then manufacturers have improved the design of IUDs, and such problems are less common with the newer models, although the risk of PID is still slightly higher, especially during the first few weeks after insertion.
How do I get one put in?
A doctor or another health professional folds down the arms of the T-shaped device and inserts it through your vagina and cervix, using a slender tube. Once it's in your uterus, the arms spring open again. It may seem strange to have a piece of plastic inside you, but you shouldn't be able to feel it at all once it's in. The insertion is often done right after your period, so you can be sure you're not pregnant. It takes only a few minutes and shouldn't be painful, although you might notice a little cramping afterward. Taking an over-the-counter painkiller like aspirin or ibuprofen before the procedure may lessen any discomfort. The IUD costs $500 to $1,000 every 10 to 12 years, not including the exam, the insertion, and a follow-up visit. After the IUD is in place, you can exercise, use tampons, or have sex as soon as you want.
Do I have to do anything?
You'll need to check regularly (once a month after your period is an easy time to remember) to make sure the IUD is still in place. Your healthcare practitioner can show you how. A small string attached to the end of the IUD hangs down into your vagina. Squat on the floor and put a finger into your vagina until you feel the thin thread (it feels a bit like fishing line).
If you can't locate the IUD's string or if you feel the device poking through your cervix into your vagina, use another birth-control method until you can get it checked out and replaced if necessary. Up to 10 percent of women who use an IUD may find that it has worked its way out of the uterus into the vagina, where it won't prevent pregnancy.
You'll also need to go back to your doctor or clinic for a checkup following your next period, three to six weeks after the IUD was put in. And, of course, you'll want to continue having an annual exam. Aside from that, the only time you'll need to make an appointment is when you want your IUD taken out. The progestin IUD must be replaced every five years, but the copper kind lasts for 12 years.
Can any woman use an IUD?
The IUD is best suited to women who've had children; once you've given birth, the device is easier to insert and more likely to stay in place. The IUD may not be a good choice for you if you've had a pelvic infection, heavy bleeding or severe pain during menstrual periods (an IUD can make both of these worse), unexplained vaginal bleeding, a recent abnormal Pap smear, or an ectopic pregnancy (in which the egg gets implanted in one of your Fallopian tubes instead of your uterus).
Certain conditions put you at increased risk for developing complications if you use an IUD, according to Planned Parenthood. You may want to consider another form of birth control if: you have had a pelvic infection following either childbirth or an abortion in the past three months, you have a sexually transmitted disease or other pelvic infection, you are or might be pregnant, your uterus is abnormally-shaped, you have very large fibroids in the uterus, you have untreated cervical cancer or cancer of the uterus, you have vaginal bleeding, your uterus tears during IUD placement, you are allergic to copper, you have severe liver disease, or you have breast cancer.
Unlike a barrier birth-control method like condoms, the IUD doesn't protect you against sexually transmitted diseases. These ailments -- including chlamydia, herpes, gonorrhea, syphilis, and AIDS -- can be even more harmful to women with IUDs, so the device isn't recommended if you already have an STD or if you're at risk of getting one because you have more than one sexual partner or you think your partner may have other partners. A small number of women may be allergic to copper and should avoid the copper IUD.
Are there any side effects or health risks?
Mild to moderate cramping and spot bleeding during the first few weeks after an IUD is inserted is common; it should disappear within a month. But about 15 percent of women continue to experience severe cramping and heavy bleeding during their periods and end up having the device removed. During the first few weeks after insertion, you have a slightly increased risk of developing pelvic inflammatory disease, an infection in the uterus or Fallopian tubes. This infection may cause scarring that will make it more difficult or impossible to get pregnant later, and in rare cases can even be fatal; that's one reason why it's important to return to your doctor or clinic for a follow-up visit soon after insertion. The IUD can also pierce the uterus while it's being put in, causing bleeding and injury, but this is quite uncommon.
Using an IUD doesn't interfere with breastfeeding and doesn't affect a nursing infant. If you've just had a baby, you should probably wait to get fitted with an IUD until your six-week postpartum checkup, when your uterus is likely to have returned to its regular size.
What symptoms might signal a problem?
Any indication of pregnancy, such as a missed period, warrants a call to your doctor or clinic. Warning signs that there may be a problem with your IUD include sharp or severe pain in the pelvic area or lower abdomen, fever with no apparent cause, a bad-smelling vaginal discharge, pain during sex, and bleeding or spotting after sex or between periods. Contact your doctor immediately if you notice any of these symptoms.
IUD at a Glance. Planned Parenthood Federation of America. 2010.
"Understanding IUDs," Planned Parenthood Federation of America, Last updated July 2005
The Intrauterine Device, pamphlet AP014. The American College of Obstetricians and Gynecologists.
Hicks, D.A. What risk of infection with IUD use? The Lancet May 25, 1998.
Mitchell D. Creinin, MD. Intrauterine Devices: Separating Fact From Fallacy. Medscape Women's Health 1(10) 1996.
Mayo Clinic. Birth Control: Copper IUD. January 23, 2010.
Mayo Clinic. Birth Control: Hormonal IUD. January 2010.