An Intra-Uterine Device (IUD) is a small, flexible, plastic device placed inside a woman’s uterus.
Mirena is the brand-name for a type of IUD that releases synthetic progesterone hormone into a woman’s body. The IUD makes it harder for sperm and eggs to move, or for a fertilized egg to lodge in the uterus. It is 99.8% effective in preventing pregnancy, making it slightly more effective than sterilization.
Because of the hormone released by Mirena, women with this IUD usually have lighter, less painful menstrual periods. Some women may have light, irregular bleeding or spotting throughout the cycle. Others have no menstrual periods at all. A few women have mood changes, less enjoyment of sex, or headaches due to the hormones in Mirena, but this is not common.
A woman can have the Mirena removed whenever she wants, although she can keep it in for up to 7 years.
Each IUD has a plastic string attached that extends into the vagina. Sometimes women and their partners are able to feel the IUD strings high inside the vagina, but usually this is not bothersome. If the string becomes uncomfortable for you or your partner, it can be adjusted by your provider.
Mirena does not protect against sexually transmitted infections (STI), including HIV/AIDS.
Insertion and Removal
First, patients may need a pre-insertion visit for discussion and pre-testing. Then, a physician or advanced practice clinician inserts the IUD. The insertion takes 5 to 15 minutes, and some women barely feel it. Others find the insertion excruciatingly painful. For most it is somewhere in between. Usually, any pain lasts only a few minutes.
Very rarely during insertion, the IUD can poke a hole in the uterus (“perforation”). If this happens, the IUD is removed, and typically the uterus heals with no problems. Sometimes in cases of perforation, the IUD moves into the abdominal cavity or becomes embedded in the wall of the uterus; it would then have to be removed surgically.
When it comes time for the IUD to be removed, it only takes a few seconds. With a speculum in the woman’s vagina, the medical professional simply pulls gently on her IUD string. It usually slips out easily, and sometimes the woman doesn’t even feel this.
It is your right to have the IUD removed anytime you want, such as if you want to get pregnant or if the bleeding or cramping becomes uncomfortable. Unfortunately, some women have had trouble getting their IUDs taken out because of the cost—either their coverage was gone when the time came for removal or their heal plan did not cover removal. Some providers are reluctant to remove IUDs for what they consider trivial reasons. It is a good idea to talk with your medical professional about these things before having the IUD put in.
Getting an IUD involves a clinic visit. To prevent infection, some clinics require women to have check-ups prior to insertion. This can include a full medical, pelvic, and breast exam, with a Pap smear, STI check, and pregnancy test. If anything unusual is found, it is addressed before the IUD is inserted. After insertion, the Mirena takes up to 7 days to become effective.
The Mirena can stay in for up to 7 years.
- Doesn’t require action from the user
- Private, usually can’t be seen or felt
- Highly effective
- Can lighten painful or heavy menstrual periods
- Can eliminate menstruation for some women, and the women like that
- Provides no protection from sexually transmitted infections
- Requires a medical visit to start or stop use
- Can cause irregular bleeding throughout the cycle or cramping
- Can eliminate menstruation for some women, and the women don’t like that
In most cases, you will not be able to have the Mirena inserted if:
- There is any possibility you are pregnant
- You have a serious pelvic infection (PID), chlamydia, or gonorrhea. These need to be completely treated before the IUD is put in
- You have a post-childbirth or post-abortion infection. These should be resolved before you get the IUD.
- You are being treated for cervical cancer – you should finish your treatment before the IUD is put in
- The shape of your uterus blocks the IUD from being inserted
- You have pelvic tuberculosis or malignant trophoblastic disease (both rare diseases)
- You currently have breast cancer
Your provider will help decide if Mirena is safe for you if:
- You gave birth or had an abortion in the past four weeks
- You have a high chance of getting sexually transmitted infections – if either you or your partner have other partners besides each other
- You have a history of a blood clot in a vein (DVT) or in your lung (pulmonary embolism), breast cancer, viral hepatitis or liver tumors
- You have AIDS or HIV
- You have benign trophoblastic disease (rare)
Life with an IUD
Many women have cramping and irregular bleeding for the first few months. If the cramping is severe and is not only during menstruation, you should ask your provider if it is simply an unpleasant effect of the IUD or if it is a sign of infection. If the amount of the bleeding is more than you usually have in your cycle, your provider can help determine if it’s serious. Both non-medical home remedies and medical treatments can help. Bleeding and cramping usually last only a few months. If they are too bothersome, you can have the IUD taken out.
IUD and pregnancy
Women with IUDs almost never get pregnant. But if they do, there is danger of a serious, fast spreading pelvic infection. So, the IUD should be removed for the woman’s safety.
An ectopic pregnancy (growing outside the uterus) can be life threatening for a woman if it’s not caught early enough. The IUD doesn’t cause these but if you become pregnant during use, there is a higher chance that the pregnancy is ectopic. If you have any signs of pregnancy, it is important to get a pregnancy test as soon as possible.
The IUD could come out, sometimes without the woman noticing. You can check for the string once a month by feeling with your finger. The string is soft, and can be tucked pretty far back in the folds of your vagina; your health care provider can show you how to find it. If you stop feeling the string, or if you or your partner feel the hard plastic part of your IUD in your vagina, it could be coming out, and you should have it checked.
IUD and infection
If a woman gets chlamydia, gonorrhea or a pelvic infection with the IUD in the uterus, it is important that the infection us treated as soon as possible. If the treatment is successful, the IUD can usually stay in place.
- Mirena Intra Uterine System (manufacturer’s website)
- ARCH Foundation gives financial assistance for Mirena to women whose insurance doesn’t cover it
- Not Your Mother’s IUD – published by National Women’s Health Network in Jan 2011