An intrauterine device is a small, plastic object shaped like a “T” that is placed in a woman’s uterus to prevent pregnancy. Also known as an IUD, this device is among the most effective and popular forms of birth control in the world. The IUD is about the size of a quarter and cannot be felt by the woman or her partner during intercourse.

IUDs come in two forms:

• Copper-containing IUD. In this device, the arms of the IUD are covered with a copper wire. The copper prevents fertilization by keeping sperm from traveling up the uterus into the fallopian tubes, where the egg is located.
  
  
• Hormone-releasing IUD. This device contains hormones. It prevents pregnancy by stopping the sperm and the egg from meeting on their way to the fallopian tubes. A levonorgestrel (a progestin) releasing version is available.

In the unlikely event that fertilization does take place, both forms of IUD offer further protection against an unwanted pregnancy by preventing the fertilized egg from implanting in the uterine wall.

Once intrauterine devices are inserted, they provide contraception for anywhere from five to 10 years, depending on the type used, or until they are removed. Less than 1 percent of women who use an IUD will become pregnant. However, these devices do not protect against sexually transmitted diseases (STDs), such as HIV infection, and in rare cases they can produce health risks.

Copper-containing IUDs can also be used as a form of emergency contraception. When inserted up to seven days after unprotected sexual intercourse, the IUD helps keep a fertilized egg from being implanted in the uterus, thus preventing pregnancy.

An intrauterine device (IUD) is a form of contraception in which a small, plastic object shaped like a “T” is placed in a woman’s uterus to prevent conception. Neither the woman nor her partner can feel the device, which is inserted by a physician in a simple procedure.

An IUD is about the size of a quarter and contains a string at one end for easy removal. It comes in two forms:

• Copper-containing IUD. In this device, the arms of the IUD are covered with a copper wire. The copper prevents fertilization by blocking sperm passage through the uterus into the fallopian tubes, where the egg is located. Even in the unlikely situation that fertilization occurs, the IUD prevents the fertilized egg from implanting in the uterine wall.
  
  This device is the longest-lasting form of reversible contraception available. A copper IUD can remain in the uterus for up to 10 years before it has to be changed, so long as a woman and her physician regularly check to make sure the IUD is placed correctly. Copper IUDs are over 99 percent effective in preventing pregnancy, but do not protect against sexually transmitted diseases (STDs), such as HIV. A copper IUD is a good alternative for women who cannot use hormonal methods of birth control, such as birth control pills, the contraceptive patch or the contraceptive ring.
  
  In addition, copper IUDs can be used as a form of emergency contraception up to seven days after unprotected sexual intercourse. When used this way, the IUD helps keep a fertilized egg from being implanted in the uterus, thus preventing pregnancy.
  
  

  

• Hormone-releasing IUD. This device contains levonorgestrel, a hormone frequently used in birth control pills. As small amounts of the hormone are released into the uterus, the cervical mucus thickens, preventing sperm from meeting the egg. The device also prevents pregnancy by slowly thinning the lining of the uterus and preventing the release of the egg from the ovary. This type of IUD has an effect on menstruation and women using this device often experience a decrease in menstrual bleeding.  
  
  A levonorgestrel-releasing IUD can remain in the uterus for up to five years before it has to be changed. It is 99.9 percent effective in preventing pregnancy, but it does not protect against STDs.

Women who later decide that they want to become pregnant can easily have the IUD removed by a physician.

IUDs are considered to be among the most effective forms of birth control, and may be more effective than birth control pills, according to the Food and Drug Administration (FDA). Of every 100 women who use an IUD, less than one will become pregnant. This compares to a rate of two to three pregnancies per 100 women who use birth control pills, and 11 pregnancies per 100 women with use of a male condom.

Although the upfront costs of IUDs tend to be higher than for some other contraceptives, the overall cost can be substantially less compared to other contraceptives, such as birth control pills or condoms, over a long period of time.

A recent survey found that some women of childbearing age are unfamiliar with the safety and effectiveness of modern IUDs, which are not as commonly used as birth control pills.

Several factors can impact whether a woman is a good candidate for intrauterine device (IUD) use. Conditions that may prohibit the use of an IUD include:

• Pregnancy.
  
  
• Copper allergy.
  
  
• Wilson’s disease (an inherited disorder in which there are excessive amounts of copper in the body).
  
  
• Allergy to levonorgestrel, silicone or polyethylene.
  
  
• Cancer of the cervix or uterus. These conditions decrease the ability of the body to fight infection and may increase the risk of vaginal infections resulting from IUD use.
  
  
• History of abnormal bleeding from the uterus. Uterine bleeding problems may be worse after an IUD is inserted, although this usually subsides over time.
  
  
• History or high risk of ectopic pregnancy.
  
  
• Abnormal uterus. This may decrease the IUD’s ability to prevent pregnancy and may increase the risk of problems. These problems can include the IUD falling out of pressing through the uterus into the cervix.
  
  
• History of pelvic inflammatory disease.
  
  
• Human immunodeficiency virus (HIV) infection or other autoimmune diseases. These diseases can interfere with the body’s ability to fight infection. Individuals with these conditions face a higher risk of developing gynecological infections associated with the IUD.
  
  
• Recent infection or complications from abortion.
  
  
• Diabetes.
  
  
• History of slow heartbeat. An IUD may increase the risk of problems related to this condition.
  
  
• Infection with other sexually transmitted diseases (STDs) in the previous 12 months. Use of an IUD may make the infection worse.
  
  
• History of surgery involving the uterus or fallopian tubes. Certain surgeries of this type may increase the likelihood of problems with an IUD. In addition, if contraception fails, the risk of ectopic pregnancy may be increased.

Women with the following conditions may also be advised against using IUDs:  

• Leukemia (cancer of the blood or bone marrow)
• Recent pelvic infection following pregnancy
• Current pelvic, cervical or vaginal infection
• Unusual discharge from the vagina
• Liver disease or liver tumor
• History of breast cancer
• Genital actinomycosis (a chronic bacterial infection)
• Rheumatic heart disease or other diseases of the heart valves
• History of long-term steroid therapy
• Intravenous drug use

Women with more than one sexual partner and women whose partners may have sexual relations with multiple partners are usually advised not to use an IUD as contraception.

The placement of the device is completed during a physician’s office visit, usually by an obstetrician-gynecologist (ObGyn). Although an IUD can be placed at any time, many physicians choose to insert the device during a woman’s menstrual period to ensure that she is not pregnant. Women who recently have had a baby must wait six weeks after delivery to allow the uterus to heal before having an IUD inserted.

The insertion procedure typically takes a few minutes. Before inserting the device, the physician will clean the patient’s vagina and cervix with an antiseptic solution. The physician inserts a speculum into the vagina, which holds the area open. An instrument called tenaculum is attached to the cervix to steady the uterus. Once the uterus is steady, the physician inserts an instrument called a “sound” to gauge the length of the cervical canal and uterus.

A thin plastic tube containing the IUD is then carefully inserted into a woman’s uterus. As the device enters the cervix, its arms bend back and spring open into a “T” shape once the IUD is in the uterus. After the physician verifies that the IUD is properly in place, the tube is withdrawn. The string attached to the device is then clipped to a proper length to prevent it from hanging too far into the vagina. Birth control protection is immediate upon insertion of the IUD.

No anesthetic is necessary during the procedure. Some women find insertion somewhat painful, similar to experiencing severe menstrual cramps. Other women experience only slight discomfort or a pinching sensation.

After the IUD has been placed in the uterus, some women may experience symptoms such as backache or dizziness. These symptoms may continue for a few minutes or as long as two days. Some women also experience spotting for the first three to six months after the procedure. It is also not unusual to experience irregular periods or periods that are heavier or prolonged. Abdominal pain and increased bleeding tend to be more common in teens than in older women.

After this adjustment period, women using the hormone-releasing IUD will likely experience a decrease in bleeding. Some will have no menstrual bleeding at all. Women who fail to get their period during the first six weeks after insertion, and those experiencing any other symptoms of pregnancy should contact their physician immediately so pregnancy can be ruled out.

Once the IUD is in place, a woman may return to all normal activities without restriction. This includes swimming, exercising, using tampons and having sex. A follow-up visit to a physician should be planned three months after insertion. During this visit, physicians will verify that the device is positioned correctly. Following this evaluation, the device can be checked annually during the woman’s routine gynecological exam.

Women should regularly check to make sure their IUD has not slipped out of place. Following each menstrual period, a woman should insert a finger into her vagina to make sure she can feel the string. If she cannot feel the string – or if she can feel the IUD – a physician should be consulted, as the IUD may not be in the right place. The following steps are recommended when checking for the IUD string:

1. Wash hands thoroughly to prevent the transmission of bacteria into the vagina.
   
   
2. Squat or place one leg on a stool to open the area. Gently insert the middle finger into the vagina and up towards the cervix.
   
   
3. Feel for the IUD string hanging down from the cervix. Do not pull the string as that action can dislodge the device.

Other signs that indicate the need to call a physician include missing a menstrual period or unusual fluids or odors coming from the vagina. 

IUDs can be removed by a physician at any time in a matter of minutes. Patients having an IUD removed can have their physician insert a new IUD during the same office visit. Women who wish to become pregnant after the device is removed can begin trying to conceive immediately. After removal, women have the same chance of conceiving as those using no method of contraception. A woman’s menstrual period will return to the pattern prior to use of the device.

Intrauterine devices (IUDs) have several advantages as a method of birth control. These include:

• Extremely effective at preventing pregnancy. In addition, women do not have to remember to take pills or perform any other action prior to intercourse. 
  
  
• Relatively low cost to insert and maintain the device.
  
  
• Immediate protection following insertion and can be removed quickly at any time.
  
  
• Low risk of side effects.
  
  
• No hormones introduced into body with a copper IUD.
  
  
• Women with an IUD who are nursing do not have to worry about passing any harmful substances to the baby through breast milk.
  
  
• The device cannot be felt by the woman or her partner during sex. The string may be felt but it is non-obtrusive.
  
  
• Reduction in menstrual bleeding (hormone-releasing IUD)

IUDs also have some disadvantages. For example, IUDs do not offer protection against STDs, such as the human immunodeficiency virus (HIV) or gonorrhea. Women who contract these infections may experience more serious health consequences if they have an IUD inserted. In addition, the risk of contracting an infection is increased in women who have an IUD and who have multiple sexual partners. Therefore, IUDs should only be used by women who have one sexual partner.

Other side effects associated with IUDs include:

• Heavier menstrual periods with more cramps (copper IUD)
  
• Lower abdominal pain (cramps) or back pain
  
• Irregular periods or cessation of periods (hormonal IUD)
  
• Acne or other types of skin disorders
  
• Breast tenderness (with hormone IUD)
  
• Headache
  
• Mood changes
  
• Nausea

These side effects, which are most common during the first three months following insertion, usually decrease over time.

In rare cases, implantation of an IUD can cause the uterus itself to be injured through perforation. In some cases, this may require surgery. Loss of an IUD is also possible. IUDs can fall out or be displaced, especially in teenagers and expulsion of the device can lead to unwanted pregnancy. Women who experience expulsion of an IUD should use a back-up form of contraception, such as a condom, and contact their obstetrician-gynecologist (ObGyn).

In addition, there is a slight chance that during insertion bacteria or an existing STD can be pushed up into the vagina and the uterus. This can result in pelvic inflammatory disease, a tubal infection that can lead to sterility or even death if left untreated. However, in the vast majority of cases, the IUD is inserted without problems.

An older type of IUD had potentially serious side effects, including pelvic infections and infertility. However, this type of IUD has been removed from the market, and such side effects very rarely occur with the new IUDs.

In less than 1 percent of cases, a woman may become pregnant despite use of an IUD. If this occurs, the IUD should be removed. The woman can then decide either to terminate the pregnancy or to carry the baby to term. In rare cases, a pregnancy that develops when a woman has an IUD in place can cause serious health problems, including:

• Miscarriage
• Premature labor and delivery
• Infection
• Death of the mother (very rare)

Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions related to intrauterine devices (IUDs):

1. Am I a candidate for an IUD? If so, which is the best type for me?
   
   
2. How effective is an IUD in preventing pregnancy?
   
   
3. What are the benefits and risks associated with my type of IUD?
   
   
4. When is the best time for me to have an IUD inserted?
   
   
5. Where will the procedure be performed?
   
   
6. How often will a physician need to check my IUD?
   
   
7. How should I check the status of my IUD?
   
   
8. What symptoms might indicate a problem with my IUD?
   
   
9. How long can I leave my IUD in place before it needs to be changed?
   
   
10. What are the chances that my IUD will fall out?
    
    
11. What should I do if I notice my IUD has moved or fallen out?
    
    
12. Am I at risk for any other gynecological conditions if I use an IUD?
    
    
13. Do I have any conditions that might prevent me from using an IUD?
    
    
14. What are my options if I become pregnant while I have an IUD?
    
    
15. How is the IUD removed when I want to try to conceive?
    
    
16. How soon can I become pregnant after removal of my IUD?