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Mirena Intrauterine System (IUS)
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Mirena is a flexible T-shaped unit that is placed inside the uterus, where it stays until removed by a health care professional. It contains a progestin hormone that is constantly released in the uterus. It is used to prevent pregnancy and can do so for five years, or until it is removed.
A health care professional will clean your vagina and cervix and then insert a thin tube of flexible plastic into your uterus. Inside the tube is the Mirena. When Mirena is in place in the uterus, the tube will be removed. Most women experience some discomfort during insertion. Insertion takes only a few minutes.
There is no single explanation of how Mirena works. It may stop release of your egg from your ovary, but this is not the way it works in most cases. It may block sperm from reaching or fertilizing your egg. It may make the lining of your uterus thin. We do not know which of these actions is most important for preventing pregnancy and most likely all of them work together.
Mirena is effective at preventing pregnancy as soon as it is inserted, although a back-up method (like condoms) is recommended until the IUD check 4-6 weeks after insertion.
Less that 1 out of every 100 women using Mirena become pregnant while using it.
Yes. For the first 3 to 6 months you will have frequent spotting or light bleeding in addition to your period. Your period may become irregular in the first 6 months, and a few women have heavy periods that last longer than normal.
After your body adjusts, your periods get shorter and you may even stop having periods. This is not harmful to your body.
After your body adjusts, your periods get shorter and you may even stop having periods. This is not harmful to your body.
Your normal ability to become pregnant returns as soon as Mirena is removed. Your health care professional can remove Mirena at any time.
Yes. Mirena is thought to be safe for breastfeeding women.
Mirena is effective for 5 years. It can decrease the blood loss, cramping and length of periods. It can also decrease anemia, or low iron levels in the blood.
There are many side effects of Mirena. The most common are: changes in your period, lower abdominal pain, acne or other skin problems, back pain, breast tenderness, headache, mood changes, and nausea.
Other side effects are possible. Talk with your nurse for more information.
Other side effects are possible. Talk with your nurse for more information.
Although rare, some Mirena users get a serious pelvic infection called Pelvic Inflammatory Disease (PID). PID can cause serious problems like infertility, ectopic pregnancy or constant pelvic pain.
Mirena may go through the uterus, which would require surgery to remove it.
Ovarian cysts have been diagnosed in about 12% of Mirena users. These usually go away on their own in a few months, but they can cause pain and sometimes require surgery.
Mirena may also come out of place by itself. You could get pregnant if this happens.
Other risks of using Mirena include cramps, dizziness and faintness with insertion; increased chance of a pregnancy outside of the uterus if a pregnancy does occur, and severe and life-threatening infection after insertion.
Mirena may go through the uterus, which would require surgery to remove it.
Ovarian cysts have been diagnosed in about 12% of Mirena users. These usually go away on their own in a few months, but they can cause pain and sometimes require surgery.
Mirena may also come out of place by itself. You could get pregnant if this happens.
Other risks of using Mirena include cramps, dizziness and faintness with insertion; increased chance of a pregnancy outside of the uterus if a pregnancy does occur, and severe and life-threatening infection after insertion.
Any woman who:
- Is pregnant or suspects pregnancy
- Might have cancer of the uterus or cervix
- Has undiagnosed, irregular bleeding between periods
- Has serious liver disease or tumor
- Has ever had breast cancer
- Has had pelvic inflammatory disease
- Has an untreated pelvic infection now