What Is It?
The intrauterine device (IUD) is a T-shaped piece of plastic about the size of a quarter that is placed inside the uterus to prevent pregnancy. Two types of IUDs are available — one is covered with copper wire, the other is coated with and releases the hormone progesterone.
How Does It Work?
The copper-coated IUD primarily prevents pregnancy by not allowing the sperm to fertilize the egg. When an IUD is coated with progesterone, it works in a similar way, but may also prevent ovulation (the release of an egg during a girl's monthly cycle) and thicken the cervical mucus, which prevents sperm from entering the uterus.
How Well Does It Work?
Over the course of 1 year, fewer than 1 out of 100 typical couples using an IUD will have an accidental pregnancy. In fact, studies indicate that the IUD is one of the most effective and safest methods of birth control. Although the IUD is an effective method of birth control, it can come out of place and therefore should be checked regularly to be sure it is in place.
In general, how well each type of birth control method works depends on a lot of things. These include whether a person has any health conditions or is taking any medications or herbal supplements that might interfere with its use. The IUD allows some flexibility for girls who cannot use a hormonal method of birth control (such as the Pill, ring, or patch). The IUD can also provide a long-term form of birth control.
Protection Against STDs
The IUD does not protect against sexually transmitted diseases (STDs). For those having sex, condoms must always be used along with the IUD to protect against STDs. One of the concerns with the IUD is that girls who have multiple partners and do not use condoms can be at greater risk for STDs, and there's the possibility that these diseases could develop into a pelvic infection. This is true, though, for all methods of birth control.
Abstinence (not having sex) is the only method that always prevents pregnancy and STDs.
Possible Side Effects
The most common side effects of the IUD include:
- spotting in between periods
- heavier periods with more cramps with the copper IUD
- irregular or loss of periods with use of the hormonal IUD
- expulsion, or loss of the IUD. For some IUD users — particularly teens — the IUD can fall out or become displaced and not work properly.
- perforation of the uterus. There is a very minimal risk of the IUD perforating the uterine wall when it is being inserted.
- acne, breast tenderness, headaches, and nausea with the hormonal IUD
In the past, one type of IUD increased a woman's risk of pelvic inflammatory disease (an infection in the upper part of a woman's reproductive system). That early type of IUD has been taken off the market and testing of the current IUDs indicate that the risk of infection is very small. Some experts feel that girls with IUDs develop pelvic infections more often than girls using other forms of contraception, but others disagree.
The other concern that used to exist with IUDs was the possibility of ectopic pregnancies, which is when a fertilized egg implants somewhere other than in the uterus. This is no longer as much of a concern. In fact scientists have found that girls with an IUD have a lower risk of having an ectopic pregnancy than girls who do not use any birth control.
Who Uses It?
IUDs are safe for some teens. However, it is more common for IUDs to come out by mistake in women who haven't had a baby, as well as in teen girls. When an IUD comes out, a girl may not even know it, leaving her unprotected.
How Do You Get It?
An IUD must be inserted into the uterus by a doctor. It is often easiest to insert during a girl's period. Copper IUDs need to be replaced by a doctor about every 10 years. IUDs with hormones must be replaced more frequently — up to every 5 years.
How Much Does It Cost?
An IUD costs about $250 plus the cost of having a doctor insert and remove it. Many health insurance plans cover these costs, and family planning clinics (such as Planned Parenthood) may charge much less.
Reviewed by: Larissa Hirsch, MD
Date reviewed: February 2007
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