Expert Health Articles

Mirena Intrauterine Device (IUD)

Allison Westcott, MDAllison Westcott, MD

Women & Children’s Center

Despite all the commercials that tout the ill-effects of the Mirena IUD (intrauterine device), it still remains one of the most popular contraceptive choices in the United States. The Mirena IUD is a small plastic “T” that contains the hormone progesterone to prevent pregnancy and alleviate heavy periods.  It is inserted into the uterus at the doctor’s office (similar to a Pap smear).

Most side effects of the Mirena IUD (including the best one – no periods!) are a result of the hormones.  The device has a total of 52 mg levonorgestrel, which is slowly released at a rate of 20 mcg per day over five years; that’s about one-tenth of a birth control pill. The hormonal side effects also occur at a much lower rate than the birth control pills. And contrary to popular belief, excessive weight gain is uncommon.

Complications requiring the removal of the IUD are uncommon and the odds of it happening are less than one-thousandth. Most IUDs that are not in the correct position are removed right away in the office.  Some require a brief surgery for removal and do not leave any lasting damage or infertility.  In fact, the American Congress of Obstetricians and Gynecologists recommends a long term birth control, such as the IUD, because the risks and side effects are less than those associated with an unintended pregnancy.

There are many types of birth control, and many are long-term.  These include the Mirena IUD, Paragard IUD (no hormone), Skyla IUD (“mini IUD”) and Nexplanon (arm implant).  Once implanted, these will last 3-10 years, are reversible, have little or no hormones with minimal side effects and can be inserted easily at your doctor’s office.  Most insurances cover these methods, and the best part is you don’t have to remember your pill each day!

Pregnancy with the IUD in is rare (about 6/1000). This is a similar failure rate to having your tubes tied. In most cases, the IUD is able to be removed early in pregnancy.  Rarely is it associated with a miscarriage or tubal pregnancy.  Occasionally, it sits in place while a normal pregnancy develops and is taken out after delivery.   

The Mirena IUD is a great choice of birth control method for many women. It can also serve as a low-risk therapy for heavy periods.  No wonder it is a popular birth control method! If you have further questions or are interested in learning more about your birth control options, have a talk with your doctor.