context: If you're looking into your options for birth control, one method you may want to think about is the IUD. They're not for everyone, but today's IUDs are considered both effective and safe for most women. And they're also long-lasting. " IUD" stands for "intrauterine device." Shaped like a " T" and a bit bigger than a quarter, an IUD fits inside your uterus. It prevents pregnancy by stopping sperm from reaching and fertilizing eggs. Five types are available in the United States. Four -- Liletta, Kyleena, Mirena, and Skyla -- release small amounts of the hormone progestin (levonorgestrel) into your body. It's the same hormone used in many birth control pills. These types of IUDs tend to make your period lighter and may be a good option if you have heavy periods. The fifth is Para Gard, also called the copper T IUD. It's hormone-free. The copper triggers your immune system to prevent pregnancy. It can cause your periods to be heavier, especially at first. But Para Gard lasts longer than hormonal IUDs. If you use an IUD correctly, your chance of getting pregnant is less than 1%. They last a long time. They're mostly hassle-free. Once you have one inserted, you don't have to think about it, and neither does your partner. It's one cost, upfront. They're safe to use if you're breastfeeding. Most healthy women can use an IUD. They're especially suited to women with one partner and at low risk of contracting an STD. IUDs don't protect against STDs. You shouldn't use one if: You have an STD or had a recent pelvic infection. You're pregnant. You have cancer of the cervix or uterus. You have unexplained vaginal bleeding. You can't use the copper IUD if you have an allergy to copper or have Wilson's disease, which causes your body hold too much copper. Hormonal IUDs are considered safe unless you have liver disease, breast cancer, or are at a high risk for breast cancer. In rare cases, the size or shape of your uterus may make it tough to place an IUD. Your doctor will insert the IUD during an office visit. She may suggest you take over-the-counter pain medication such as ibuprofen a few hours before the procedure to offset cramping. The procedure starts out similar to getting a Pap smear. You'll put your feet in stirrups. The doctor will then place a speculum in the vagina to hold the vagina open. The doctor will put the IUD in a small tube that she'll insert into your vagina. She'll move the tube up through the cervix and into the uterus. Then she'll push the IUD out of the tube and pull the tube out. Strings attached to the IUD will hang 1-2 inches into the vagina. The procedure is uncomfortable, and you may have cramps and bleeding, but they tend to go away in a few days. Some women may also feel lightheaded from the pain. You can have most IUDs placed at any time in your cycle. But it may be more comfortable to have one inserted while you're having your period. This is when your cervix is most open. The non-hormonal Para Gard is effective as soon as it's inserted. If it's put in during your period, hormonal IUDs start working right away. Otherwise, this type may take up to 7 days to be effective. This depends on what kind of IUD you get. 3 years for Skyla 5 years for Kyleena, Liletta, and Mirena 10 years for Para Gard With hormonal IUDs, many women have fewer cramps. For the first few months, some women have irregular spotting. Eventually, most women have light periods or no period at all. Pregnancies rarely happen with IUDs, but if not having a period will make you constantly worry that you're pregnant, you may want to consider the copper IUD instead. The copper Para Gard may make periods heavier and cramping worse. This may go away after a few months. Your partner shouldn't be able to feel anything, but if he does, it will only be minor contact with the strings of the IUD. This shouldn't cause any discomfort. The strings soften the longer you have the IUD and can be trimmed shorter. IUDs are safe. Some women do have side effects, but most are mild. Serious problems with them are rare. Some women feel lightheaded right after their doctor inserts the IUD, but the feeling should pass after a few minutes. In the first few days after insertion, you can expect to have period-like cramps. You're very unlikely to get pregnant while you have an IUD. But if it happens, it raises your risk for miscarriage, infection, and early labor and delivery. It also puts you at risk for an ectopic pregnancy, when a fertilized egg implants outside of your uterus. Let your doctor know if you think you might be pregnant or if you have belly pain or vaginal bleeding. About 1 in 10 women will get ovarian cysts in the first year after they get an IUD. They're usually harmless and go away on their own within 3 months. But some can cause bloating, swelling, or pain in the lower belly. If a cyst ruptures, it will cause severe pain. See your doctor if you have these symptoms. An IUD slightly raises your odds for pelvic inflammatory disease ( PID), which is an infection of the uterus, fallopian tubes, or ovaries. Signs include belly pain, pain during sex, smelly vaginal discharge, heavy bleeding, chills, and fever. Let your doctor know about these symptoms right away. It's important to treat PID quickly to prevent more serious problems. It's rare, but an IUD can poke through the wall of your uterus as your doctor puts it in. It's called perforation. If it happens, your doctor will have to remove the device. Your doctor will check your device during your regular office visits. Your cervix should hold the IUD in place, but in rare cases, it can fall all the way or part of the way out. This is more likely if: You don't have children. You're under 20 years old. You had the IUD put in right after having a baby or after having a second-trimester abortion. You have fibroids in your uterus. Your uterus is an unusual size or shape. IUDs are more likely to come out during your period. You may see the device on a pad or tampon. Check periodically to make sure you can feel the strings. If they feel shorter or longer or if you can feel the IUD itself pushing against your cervix, it may have moved. If this happens, contact your doctor. Using an IUD shouldn't affect your ability to have children later on. If you want to get pregnant, ask your doctor to take out your IUD. Your cycle should return to normal as soon as the IUD is removed. Your doctor will take out the IUD in her office. It should only take a few minutes. You'll put your feet in stirrups and the doctor will use forceps to slowly pull the IUD out. You may have some cramping and bleeding, but this should go away in 1-2 days.