What is an IUD?

An IUD, or intrauterine device, is a small contraceptive device made of flexible plastic. It's inserted into the uterus, where it provides safe, highly effective long-term contraception.

There are two types of IUDs currently available in the United States. One uses copper and the other uses the synthetic hormone levonorgestrel, a form of progestin. (IUDs don't contain estrogen.)

The Copper T380A (brand name ParaGard) is wrapped in fine copper wire and lasts for ten to twelve years. The hormonal IUDs are Mirena, which lasts for five years and Liletta and Skyla, which last for three years.Both copper and hormonal IUDs are T-shaped and less than 1.5 inches long and can be removed at any time.

An IUD is a good option for women who want a highly effective, long-term, easily reversible method of contraception. It can be an appropriate choice for women who can't use certain hormonal methods like birth control pills or who aren't good pill takers. Keep in mind that, like the Pill, an IUD won't protect you from sexually transmitted infections (STIs).

The copper IUD may also be used for emergency contraception. If it's inserted within five days after unprotected sex, it's more effective than taking emergency contraceptive pills. Plus you can just leave it in for ongoing contraception.

How does an IUD prevent pregnancy?

Both types of IUDs work primarily by preventing sperm from fertilizing an egg. The copper IUD releases copper into the uterus, which works as a spermicide. The others release a form of the hormone progestin into the uterus. The progestin thickens the cervical mucus so that sperm can't reach the egg. In some women, progestin may also prevent ovulation.

In the unlikely event that an egg does get fertilized and survives, both types of IUD cause inflammation in the uterus that makes it harder for the egg to implant there. Hormonal IUDs also cause thinning of the uterine lining, making implantation more difficult.

Can I use an IUD if I'm breastfeeding?

Yes. Neither type of IUD affects the quality or quantity of breast milk.

How effective is the IUD?

The IUD is one of the most reliable forms of contraception. Annual failure rates are well under 1 percent.

This means that IUDs are as effective as surgical sterilization. Unlike with sterilization, though, an IUD is reversible – you'll be fertile again shortly after an IUD is removed.

Other reversible methods, including the Pill, patch, ring, or shot, can be very effective, but only in women who use them correctly and consistently. In actual practice, these methods have failure rates that are much higher than those seen in women using IUDs.

That's because the IUD virtually eliminates the possibility of human error. All you have to do is check the device each month to be sure it's still in place.

Will the IUD affect my ability to get pregnant after it's removed?

No. An IUD can be taken out at any time during your cycle, and you can start trying to get pregnant right away. Typically, your fertility will be the same as it was before you had the device put in.

How do I get an IUD?

Ask your healthcare provider whether she inserts them. If she doesn't, ask her to direct you to another provider or a clinic where you can have one put in.

The provider who inserts your IUD will want to make certain you're not pregnant and may perform a sensitive pregnancy test. She'll want to be sure you don't have an infection that could cause pelvic inflammatory disease (PID), so she'll question you about your sexual history and examine you for signs of a problem. She may test you for chlamydia and gonorrhea. And during the pelvic exam, she'll also be checking the position of your uterus.

If you're found to be a good candidate for the IUD, one can usually be inserted right away. (If your caregiver is waiting for test results, you might have to schedule another visit for the insertion.)

You can also have an IUD inserted right after giving birth, whether you've delivered vaginally or by c-section.

How is the IUD inserted?

When it's time for the insertion, your provider places a speculum in your vagina and cleans the vagina and cervix with an antiseptic solution. She then uses an instrument to grasp your cervix, which may cause a brief, sharp pain. This instrument allows her to straighten your cervical canal and draw the uterus closer to the vagina so she can measure the depth of your uterine cavity. Then she inserts the IUD, using a narrow applicator tube. You will likely feel a painful but temporary cramp at this time.

Once the IUD is in place, the applicator is removed and the arms spring open into the T formation. It may seem strange to have a piece of plastic inside you, but you shouldn't be able to feel it once it's inserted. The two strings attached to the end of the IUD will hang down through your cervix and be trimmed so that they protrude only slightly into your vagina. The whole procedure takes just a few minutes.

You may feel some cramping or back pain for a few days after the procedure. Taking ibuprofen about an hour before the procedure and as needed afterward should help lessen any discomfort. You can use tampons as soon as you want after insertion.

Your provider may recommend that you come back for a checkup following your next period, a few weeks to a month after the IUD is put in. She'll check that the IUD is still in place and make sure that you have no signs of an infection. Your caregiver will also check your IUD at your annual pelvic exam.

Do I need to use a backup form of contraception after insertion?

The copper IUD is effective as soon as it's in place. The progestin IUD is effective immediately if it's inserted within seven days after the start of your period. Otherwise, you'll need to use a backup form of contraception (such as condoms) for the first seven days after you get your IUD.

Some experts recommend using a backup method for the first month after an IUD is inserted because that's when the device is most likely to be expelled.

How do I make sure my IUD is still in place?

You'll need to check regularly because your IUD can get pushed through your cervix – even expelled completely – without your even noticing it.

How to check

Your healthcare provider can show you how to check your IUD. First wash your hands. Then squat on the floor, sit on the toilet, or put one leg up on a chair. Put a finger into your vagina and feel for your cervix. You should be able to feel two strings coming out of it. They may feel a bit like fishing line. Just feel for the strings with the tip of your finger – don't tug on them.

If you can't locate the IUD strings or if you feel the device poking through your cervix into your vagina, see your caregiver to have it checked out. Be sure to use another birth control method (such as condoms) in the meantime because the IUD isn't effective if it's not completely inside your uterus.

If you can't feel the strings and your caregiver can't find them either, an ultrasound will be done to see whether the IUD is still in place. Fewer than 5 percent of women who use an IUD expel it during the first year. Teenagers, women who have never had children, women who have an abnormally heavy menstrual flow, and those who have severe menstrual cramps may be somewhat more likely to expel an IUD.

If your IUD is poking out of your uterus or was completely expelled, you can get another one put in, but there's a 30 percent chance that it'll come out again.

When to check

Some providers advise checking once a week for the first month and at least monthly after that. Just after your period ends is a good time to check, because an IUD is more likely to be expelled during menstruation than at other times.

If you have the progestin IUD and are no longer having monthly periods, choose a day that will be easy to remember – like the first of every month. Also check after any period you do have.

How is the IUD removed?

When it's time to have your IUD removed, your provider inserts a speculum into your vagina, cleans your cervix, clamps a small forceps on the strings, and grasps the cervix with an instrument to straighten out the cervical canal. She then pulls gently on the strings and the IUD comes out. The procedure takes less than 10 seconds.

The arms of the IUD are flexible and will fold up as they come through your cervix, but you may feel a cramp. If you'd like to continue using an IUD, you can have a new one inserted during the same visit.

An IUD can be removed at any time during your menstrual cycle if you're ready to try to conceive. If you're switching to another method of contraception, however, discuss the timing with your provider. You may need to start using your new method before the IUD is removed to make sure you're completely protected.

How much does an IUD cost?

Many health insurers cover IUDs. In fact, thanks to the Affordable Care Act, new insurance plans must cover all FDA-approved contraceptive methods with no additional cost to you. Plans that existed on March 23, 2010 – and some religiously affiliated employers – are exempt, but many are complying with the changes anyway.

If you're paying out of pocket, you can expect to spend $500 to $1,000 in addition to the cost of the office visits. While this may sound like a lot, consider that the IUD lasts three to twelve years, which makes it a whole lot less expensive over time than birth control pills. Family planning clinics tend to offer the lowest prices and may also have sliding-scale fees to make the IUD even more affordable.

How will the IUD affect my period?

With the progestin IUD, it's common to have very irregular bleeding and spotting in the first three to six months. Eventually, your periods may become much lighter and shorter than they were before the IUD and you may have less cramping. By the end of the first year, many women have infrequent periods or stop getting them altogether.

The copper IUD may also cause irregular bleeding and spotting during the first few months. Your periods might become longer and heavier, particularly in the first three to six months after insertion. They may lighten somewhat over time but still remain heavier than they were before the IUD. Some women also have more cramping than before.

Women with heavy bleeding may be treated with medication that sometimes helps lighten the flow and are given iron supplements if needed to prevent or treat anemia. If you continue to have heavy bleeding, you might need to have the copper IUD removed. (You may have it replaced with a progestin IUD if you wish.)

Does the IUD cause any other side effects?

The IUD is unlikely to cause any serious side effects. For a small number of women, the progestin IUD causes side effects such as acne, headaches, breast tenderness, and depression, which generally get better over time.

On the plus side, many providers recommend the progestin IUD for women who suffer from heavy, prolonged, or painful menstruation because it tends to lighten their periods or even suppress them altogether. And because they lose less blood, women using this IUD are less likely to develop iron-deficiency anemia, a condition that can cause fatigue and other symptoms.

By the way, because the IUD is placed in your uterus, not your vagina, neither you nor your partner will feel the device during intercourse, though your partner may feel the threads.

What symptoms might signal a problem?

Warning signs that there may be a problem include sharp or severe pain in the pelvic area or lower abdomen, fever with no apparent cause, an unusual or bad-smelling vaginal discharge, genital sores, pain during sex, bleeding or spotting after sex or between periods, and severe or prolonged vaginal bleeding.

Call your caregiver right away if you notice any of these symptoms or if you have any indication that you're pregnant, such as a missed period (with the copper IUD), sore breasts, or morning sickness. It's also a good idea to call your caregiver to rule out pregnancy the first time you miss a period with the progestin IUD. After that, it's unnecessary unless you have other symptoms.

Also call if you can't feel the threads, if the threads feel longer or shorter than usual, or if you or your partner feels the end of the IUD protruding from your cervix. Finally, call your caregiver if you think you may have been exposed to an STI, even if you don't have any symptoms.

What happens if I do get pregnant while I have an IUD?

The first thing your healthcare provider will do is check to make sure you don't have an ectopic pregnancy by giving you a blood test, a vaginal exam, and an ultrasound.

If your pregnancy is not ectopic, you can choose whether to continue the pregnancy. If you choose to continue it, your caregiver will remove the IUD, if possible. She can remove the device easily without an invasive procedure as long as the strings are visible. There's a slight risk that removing the IUD will cause you to lose the pregnancy, but you're much more likely to lose the baby to infection (and put your own health at risk) if you keep it in.

In the unlikely event that the IUD can't be easily removed and you choose to continue the pregnancy, you'll be carefully monitored. You're at risk for preterm delivery if you get pregnant with an IUD, particularly if it's left in place.

A note on switching birth control methods

Switching birth control methods can be tricky. You don't need to wait until the beginning of a menstrual cycle to start a new method. Taking a break between methods is not recommended either. In fact, you may need to start your new method a week before you stop using the old method.

The Reproductive Health Access Project has posted a chart that explains how to switch contraceptives while minimizing the risk of pregnancy.

Note:

This article was reviewed by Andrew M. Kaunitz, professor of obstetrics and gynecology at the University of Florida College of Medicine in Jacksonville.