Mirena (Levonorgestrel-releasing intrauterine system)

Mirena (Levonorgestrel-releasing intrauterine system)

Print Friendly, PDF & Email

What is the hormone-releasing IUD?

Mirena (levonorgestrel-releasing intrauterine system) is a hormone-releasing system placed in your uterus to prevent pregnancy for as long as you want for up to 5 years. Mirena also treats heavy periods.

Mirena is the only hormone-releasing IUD available in Australia.

Mirena is a small plastic device in the shape of a ‘T’. It is placed inside the uterus (womb). The IUD has a fine nylon string attached to it. When the IUD is in place, the string comes out through the cervix (the neck of the uterus) into the top end of the vagina. If you place your finger high up inside your vagina, you can check that the string is there and know the IUD is still in place. The string also makes it easy for a doctor to remove the IUD.

The hormone-releasing IUD can stay in place for up to five years. 

How does the hormone-releasing IUD work?

The hormone makes the mucus in the cervix thicker so that sperm cannot get into the uterus. It also affects the ability of the sperm to move through the uterus and egg to move through the fallopian tubes, which reduces the chance of an egg being fertilised. It also changes the lining of the uterus, making it less suitable for a pregnancy. It can also sometimes stop your ovaries from releasing an egg. It also reduces menstrual bleeding which helps women who have heavy periods 

How effective is the hormone-releasing IUD?

The hormone-releasing IUD is at least 99% effective. This means that on average, if 100 women use an IUD for one year, it is possible that one of them could become pregnant. 

Who can use the hormone-releasing IUD?

  • Women who want a reliable, long term BUT reversible contraceptive method
  • Women who have completed their families and those who are spacing their pregnancies
  • Women who are breastfeeding
  • Women who have heavy periods 

Who should not use this type of IUD?

Do not use Mirena if you:

  • Are or might be pregnant
  • Have an untreated pelvic infection now or have had a serious pelvic infection in the past 3 months
  • Can get infections easily. For example, if you have:
    • Multiple sexual partners or your partner has multiple sexual partners
    • Problems with your immune system
    • Intravenous drug abuse.
  • Have or suspect you might have cancer of the uterus or cervix
  • Have bleeding from the vagina that has not been explained
  • Have liver disease or liver tumor
  • Have breast cancer or any other cancer that is sensitive to progestin (a female hormone), now or in the past
  • Have a condition of the uterus that changes the shape of the uterine cavity, such as large fibroid tumors
  • Are allergic to levonorgestrel, silicone, polyethylene, silica, barium sulfate or iron oxide 

Benefits with using a hormone-releasing IUD

  • It is a very effective form of contraception
  • It is a long acting (5 years) and reversible method of contraception
  • It is immediately reversible so when it is removed you return to your usual level of fertility.
  • It is a birth control method that you do not need to take daily
  • For women who have heavy periods, the hormone- releasing IUD can be a very good choice as it usually makes bleeding much lighter and sometimes stops periods all together 

Possible problems with using a hormone- releasing IUD 

All procedures carry some degree of risk. While health care professionals make every attempt to minimise risks, complications can still occur. It is not possible to outline every possible side effect or rare complication of a procedure. However, it is important that you have enough information about possible complications to fully weigh up the benefits and risks of the procedure. Most complications are uncommon. The following possible complications are listed to inform you, not to alarm you. There may be other complications that are not listed. 

Pelvic inflammatory disease (PID). Some IUD users get a serious pelvic infection called pelvic inflammatory disease. It occurs in about one in every 500 insertions and usually happens in the first 3 weeks after insertion. PID is usually sexually transmitted. You have a higher chance of getting PID if you or your partner has sex with other partners. PID can cause serious problems such as infertility, ectopic pregnancy or pelvic pain that does not go away. PID is usually treated with antibiotics. Signs of PID can include: long-lasting or heavy bleeding, unusual vaginal discharge, low abdominal (stomach area) pain, painful sex, chills, or fever. 

Life-threatening infection. Life-threatening infection can occur within the first few days after Mirena is inserted. You need urgent medical attention if you develop severe pain or fever shortly after Mirena is placed. 

Perforation. Mirena may become attached to (embedded) or go through the wall of the uterus. This is called perforation. It occurs in about one in every thousand insertions. If this occurs, Mirena may no longer prevent pregnancy. If perforation occurs, Mirena may move outside the uterus and can cause internal scarring, infection, or damage to other organs, and you may need surgery to have Mirena removed. The risk of perforation is increased in breastfeeding women. You will need to have an operation to remove it safely.

Pain, bleeding or dizziness during and after insertion. If these symptoms do not stop within 30 minutes, Mirena may not have been placed correctly.

If you haven’t had children or if you have only had caesarean deliveries, the IUD may be more difficult to insert.

Some women may experience hormonal side effects, such as bloating or skin changes, but this is uncommon because the dose of hormone is so small 

Expulsion. Mirena may come out by itself. This is called expulsion. It occurs in about five out of every 100 women with an IUD. It is most common in the few months after the insertion procedure. You may become pregnant if Mirena comes out. If you think that Mirena has come out, use a backup birth control method like condoms and spermicide and seek medical attention.  

Changes in bleeding. Women may have irregular bleeding and spotting in the first 3 to 6 months after the Mirena is inserted. Bleeding usually settles down and periods become shorter and lighter. About 2 out of 10 women stop having periods after 1 year of Mirena use.

Missed menstrual periods. About 2 out of 10 women stop having periods after 1 year of Mirena use. If you do not have a period for 6 weeks during the early time of Mirena use, you need medical attention to exclude pregnancy. When Mirena is removed, your menstrual periods will come back.

Cysts on the ovary. About 12 out of 100 women using Mirena develop a cyst on the ovary. These cysts usually disappear on their own in a month or two. However, cysts can cause pain and sometimes cysts will need surgery.

Pregnancy. Occasionally a woman becomes pregnant with an IUD in place. This happens in fewer than one in 100 women who have an IUD. You need urgent medical attention if you think you are pregnant.

If you get pregnant while using Mirena, you have a risk (1:3 chances) that you have an ectopic pregnancy. This means that the pregnancy is not in the uterus. Unusual vaginal bleeding or abdominal pain may be a sign of ectopic pregnancy. Ectopic pregnancy is a medical emergency that often requires surgery. Ectopic pregnancy can cause internal bleeding, infertility, and even death.

There are also risks if you get pregnant while using Mirena and the pregnancy is in the uterus. Severe infection, miscarriage and premature delivery can occur with pregnancies that continue with an intrauterine device (IUD). Because of this, it is advisable for the Mirena to be removed, even though removing it may cause a miscarriage.

If you continue your pregnancy, you need urgent medical attention if you get flu-like symptoms, fever, chills, cramping, pain, bleeding, vaginal discharge, or fluid leaking from your vagina. These may be signs of infection.

It is not known if Mirena can cause long-term effects on the fetus if it stays in place during a pregnancy. 

How do you get the hormone-releasing IUD?

You need to go to a specially trained doctor for an IUD. You are usually asked to make two visits.

On the first visit the doctor will take a history about your general and reproductive health. You will need to have a vaginal/pelvic examination, and if necessary a Pap test and possibly a test for infections. You will also be given a script to get the hormone- releasing IUD from a pharmacy before your insertion visit. The procedure will be explained to you. It takes about 10 minutes. Some women may find the experience uncomfortable while others may find it quite painful. You do not have to fast before the procedure. You may feel faint during or after the insertion and you might need to rest for a while before you leave the clinic. You should allow about an hour to be at the clinic.

On the second visit you will have the IUD inserted. You need to take simple analgesia (Panadol and Neurofen) one hour before the IUD is inserted. You may be commenced on a course of oral antibiotics for 5 days to aid in preventing infection.

Sometimes IUD is inserted in hospital under general anaesthetics, for example

  • If you have not had children
  • If you have a history of low blood pressure, tendency to faint and anxiety
  • If it is difficult to insert in office due to stenotic (tight) cervix
  • If the Mirena is used to treat heavy menstrual or irregular bleeding and a condition called hyperplasia or cancer are needed to be excluded first, a minor procedure called hysteroscopy is needed to be done under general anaesthetics prior to insertion of Mirena. Hysteroscopy is a procedure to examine the inside of the uterus. A thin telescope “a hysteroscope” is passed through the cervix to inspect the lining of the uterus, and to look for any abnormalities. A small sample (biopsy) of the uterine lining is usually taken and sent to a pathologist for examination.

What to expect after an IUD insertion

You may have period-like cramps and bleeding or spotting in the first few days after the IUD is inserted. Taking paracetamol and Neurofen regularly for couple of days and holding a hot water bottle on your abdomen may help to relieve any discomfort. If cramps, spotting or pain last more than a few days, you need medical attention. You should avoid vaginal sex, tampons, swimming and baths for few days, to reduce the risk of infection.

You will need a check-up, four to six weeks after the IUD insertion. After that you will need a check-up every two years with your regular Pap test.

Remember, you may have irregular bleeding and spotting in the first few months after the Mirena is inserted. Bleeding usually settles down and periods become shorter and lighter.

How is the hormone-releasing IUD taken out?

The IUD can stay in place for five years. If you want to get pregnant or you decide that you do not want to have the IUD for other reasons, it can be removed earlier. A special instrument is used to remove the IUD by gently pulling on the string. This only takes a couple of minutes. Some women find it a little uncomfortable and some don’t feel much at all. 

If the string cannot be seen or there is a chance that the Mirena is not in the proper place or evidence that it is embedded in the wall of the uterus, The Mirena is needed to be removed under direct vision using a hysteroscope/Laparoscope under general anaesthetics in the operating theatre to avoid or at least minimize damages to the uterus or other organs to which it might be attached to.

Your queries are best answered over the phone, our friendly reception staff would be happy to assist you with your enquiry, contact us on +02 8824 4998

Book an Appointment