IUD: A Safe, Underused Contraceptive

The intrauterine device (IUD) is one of the most effective, reversible methods of birth control available. It is easy to use, has a low rate of complications and is highly acceptable to women who choose it for their contraceptive method. Over the past few years the number of women asking about and utilizing IUDs has increased but still only a few percent of women in the United States use an IUD for their contraceptive method compared to 30% of women in Scandinavian countries.

Many types of IUDs have been used over the years. Currently there are two types available in the United States. The most commonly used is called ParaGard. This consists of a plastic T shaped device a few inches long that is wrapped with copper. It is inserted through the cervix into the uterine cavity (an almost painless procedure that is performed in the office). Once in place it is effective for at least 10 years. The ParaGard protects against pregnancy by decreasing the number of sperm that can reach the egg, thus preventing fertilization. It also interferes with the movement of eggs into the uterus. It is more than 99% effective in preventing pregnancy. Side effects are minimal with some women reporting a temporary increase in menstrual flow and cramping, much of which can be controlled with over the counter analgesics.

A different type of IUD, Mirena, has been available in this country for almost 5 years. It releases a low dose of the progestin levonorgesterol into the uterus. It is also more than 99% effective in preventing pregnancy and can be left in place for 5 years. The Mirena has the added advantage of significantly reducing menstrual blood loss in women who use it. In fact it is successfully used to treat women who have heavy periods. About 20% of women who use the Mirena will have no menses the remainder will have significantly decreased flow but may have irregular spotting

Given its effectiveness, minimal side effects and safety, why do more women not use an IUD for contraception? In the 1970’s the Centers for Disease Control found that users of a particular type of IUD, called the Dalkon Shield, had an increase in pelvic infections and complicated pregnancies. In 1974 this device was removed from the market. Subsequent research revealed that the design of that particular IUD allowed bacteria to ascend into the uterus resulting in serious problems for affected women. For many years after this it was thought that any IUD increased the risk of serious pelvic infections and infertility. However, more recent research has shown that the risk of infection is limited to women who contract a sexually transmitted disease. There is a small risk of infection at the time of insertion but this can be minimized with proper training. In women who are not at risk for acquiring a sexually transmitted disease there is virtually no risk of the IUD causing pelvic infection and subsequent infertility. Unfortunately many women still associate the IUD with infectious complications.

The ParaGard is a good contraceptive choice for all women who are not at risk for acquiring a sexually transmitted disease, including women who have not had a child. The Mirena is a very good option for women who have heavy menstrual bleeding. Other contraindications to IUD use include an allergy to copper (ParaGard only), a uterine abnormality, an unresolved abnormal pap smear or a current or recent pelvic infection.

When properly selected and counseled, the majority of women who choose an IUD will be quite satisfied with their choice of contraceptive. Complications are minimal; the method is very effective and fertility is immediately restored when the IUD is removed.