Intrauterine devices (IUDs) are small, flexible, T-shaped plastic devices that are inserted into the uterus.
In the United States, approximately 10% of women use long-acting reversible contraception (LARC). Intrauterine devices (IUDs) are the most commonly used LARC. IUDs are popular because of their advantages as a contraceptive method, including being highly effective and having minimal side effects. Also, IUDs need to be changed only every 3, 5, 8, or 10 years, avoiding the need to use a daily, weekly, or monthly contraceptive method.
IUDs must be inserted and removed by a doctor or other health care professional. Insertion takes only a few minutes. Insertion may be painful, so an anesthetic may be injected into the cervix before the IUD is inserted. Removal usually causes minimal discomfort.
IUDs prevent pregnancy by
Killing or immobilizing sperm
Preventing sperm from fertilizing the egg
Creating an inflammatory reaction inside the uterus that is toxic to sperm
Understanding Intrauterine Devices
Intrauterine devices (IUDs) are inserted by a doctor into a woman’s uterus through the vagina. IUDs are made of molded plastic. Two types of IUDs release a progestin called levonorgestrel. The other type is T-shaped and has a Intrauterine devices (IUDs) are inserted by a doctor into a woman’s uterus through the vagina. IUDs are made of molded plastic. Two types of IUDs release a progestin called levonorgestrel. The other type is T-shaped and has acopper wire wrapped around the base and on the arms of the T. A plastic string is attached to the IUD. The string enables a woman to make sure the device is still in place and a doctor to easily remove it. |
In the United States, available IUDs include levonorgestrel-releasing IUDs and a In the United States, available IUDs include levonorgestrel-releasing IUDs and acopper IUD.
Different levonorgestrel-releasing IUDs last for different lengths of time: 3, 5, or 8 years. For all types, pregnancy occurs only in less than 1.5% of women. Different levonorgestrel-releasing IUDs last for different lengths of time: 3, 5, or 8 years. For all types, pregnancy occurs only in less than 1.5% of women.
The copper IUD is effective for at least 10 years. When it is left in place for 12 years, fewer than 2% of women become pregnant.
One year after removal of an IUD, 80 to 90% of women who try to conceive do so.
Most women, including those who have not had children, and adolescent girls, can use IUDs. However, IUDs should not be used when the following conditions are present:
A pelvic infection, such as a sexually transmitted infection or pelvic inflammatory disease
A structural abnormality that distorts the uterus
Unexplained bleeding from the vagina
Cancer of the cervix or cancer of the lining of the uterus (endometrium)
Pregnancy
For levonorgestrel-releasing IUDs, For levonorgestrel-releasing IUDs,breast cancer or an allergy to levonorgestrelor an allergy to levonorgestrel
For copper IUDs, Wilson disease or an allergy to copper
Having had a sexually transmitted infection, pelvic inflammatory disease, or a mislocated (ectopic) pregnancy in the past does not prevent women from using an IUD.
An IUD can be inserted at any time during the menstrual cycle, as long as the woman has not had unprotected sex since her last period. If unprotected sex has occurred, a pregnancy test is required before insertion, and another form of contraception should be used until the test confirms she is not pregnant. Pregnancy must always be ruled out before IUD placement, except when a copper IUD is being used for emergency contraception. In that case, insertion within 5 days of unprotected sex is nearly 100% effective in preventing pregnancy, and the device can then remain in place for long-term birth control if desired. Levonorgestrel-releasing IUDs are not yet approved for emergency contraception and should only be inserted once pregnancy is excluded.An IUD can be inserted at any time during the menstrual cycle, as long as the woman has not had unprotected sex since her last period. If unprotected sex has occurred, a pregnancy test is required before insertion, and another form of contraception should be used until the test confirms she is not pregnant. Pregnancy must always be ruled out before IUD placement, except when a copper IUD is being used for emergency contraception. In that case, insertion within 5 days of unprotected sex is nearly 100% effective in preventing pregnancy, and the device can then remain in place for long-term birth control if desired. Levonorgestrel-releasing IUDs are not yet approved for emergency contraception and should only be inserted once pregnancy is excluded.
Before the IUD is inserted, doctors may recommend testing for sexually transmitted infections (STIs) based on a woman's risk factors. However, doctors do not need to wait for STI test results before inserting the IUD. If results are positive, the STI is treated, and the IUD is left in place. If doctors observe a discharge that contains pus just before the IUD is to be inserted, an IUD is not inserted. In such cases, STI testing is done, and antibiotics are started immediately, without waiting for test results. The IUD is then inserted after treatment of the infection is complete.
An IUD may be inserted immediately after a miscarriage or an abortion that occurs during the 1st or 2nd trimester and immediately after the placenta is delivered after a cesarean delivery.
Photograph © Hank Morgan/Photo Researchers Inc.
The uterus is briefly contaminated with bacteria at the time of insertion, but an infection rarely results. IUD strings do not provide access for bacteria. An IUD increases the risk of a pelvic infection only during the first month of use. If an infection develops, it is treated with antibiotics. The IUD can be left in place unless the infection persists after treatment.
A routine follow-up visit after IUD insertion is not necessary. However, women should see their doctor if they have problems such as pain, heavy bleeding, abnormal vaginal discharge, or fever, if the IUD is expelled, or if they are dissatisfied with the IUD.
Possible problems
Bleeding and pain are the main reasons that women have an IUD removed, accounting for more than half of all removals before the usual replacement time. The copper IUD increases the amount of menstrual bleeding and may cause cramps. NSAIDs can usually relieve the cramps. Levonorgestrel-releasing IUDs cause irregular bleeding during the first several months after insertion. But then after 1 year, menstrual bleeding stops completely in up to 20% of women.IUD increases the amount of menstrual bleeding and may cause cramps. NSAIDs can usually relieve the cramps. Levonorgestrel-releasing IUDs cause irregular bleeding during the first several months after insertion. But then after 1 year, menstrual bleeding stops completely in up to 20% of women.
Typically, IUDs are expelled in fewer than 5% of women during the first year after insertion, often during the first few weeks. Sometimes a woman does not notice the expulsion. Plastic strings are attached to the IUD so that if she wishes, a woman can check every so often to make sure that the IUD is still in place. However, a woman typically has bleeding or pain if an IUD is expelled or is in the wrong position. If another IUD is inserted after one has been expelled, it usually stays in place. If doctors suspect that the IUD has been expelled, women must use another form of birth control until the problem is resolved.
Rarely, the uterus is torn (perforated) during insertion. Usually, perforation does not cause symptoms. It is discovered when a woman cannot find the plastic strings and ultrasound or an x-ray shows the IUD located outside the uterus. An IUD that perforates the uterus and passes into the abdominal cavity must be surgically removed, usually using laparoscopy, to prevent it from injuring and scarring the intestine.
If women conceive with an IUD in place, they are more likely to have a pregnancy located outside of the uterus (ectopic). Nonetheless, the overall risk of an ectopic pregnancy is much lower for women using IUDs than for those not using a contraceptive method because IUDs prevent pregnancy effectively.
Similar to other hormonal contraceptives, there are conflicting data regarding whether IUDs slightly increase the risk of breast cancer.
Possible benefits
In addition to providing effective birth control, levonorgestrel-releasing IUDs may reduce the risk of In addition to providing effective birth control, levonorgestrel-releasing IUDs may reduce the risk ofuterine (endometrial) cancer and cancer of the ovaries.
If a woman has had unprotected sex within the past 7 days, certain IUDs may be used as emergency contraception.
Drugs Mentioned In This Article
