Hormone-releasing IUD (Mirena)
What Is The Hormone-Releasing IUD?
The only hormone-releasing intrauterine device (IUD) available in Australia is called Mirena®. It is a small plastic device in the shape of a 'T' with a hormone called levonorgestrel in its stem. It is placed inside the uterus (womb) to prevent pregnancy. 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 feel high up inside your vagina with your finger, 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 and egg to move through the uterus and 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.
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?
Most women who want a reliable, long term contraceptive can use it.
Women who have completed their families, those who are spacing their pregnancies as well as women who have not had a pregnancy can all potentially use a hormone-releasing IUD.
Women who are breastfeeding can use a hormone-releasing IUD.
It reduces menstrual bleeding which helps women who have heavy periods.
Who Should Not Use This Type of IUD?
You should not use a hormone-releasing IUD if:
- you could be pregnant
- you have a current pelvic infection - this is called pelvic inflammatory disease (PID)
- you have abnormal bleeding from your vagina, that has not been diagnosed
- you are waiting for treatment for cervical cancer or cervical changes
Situations That Require Further Consideration Before Choosing an IUD
If any of these apply to you, you will need to talk them over with your doctor before deciding to use a hormone-releasing IUD:
- you have had a recent sexually transmitted infection (STI)
- you have a congenital heart or valve disease
- you have fibroids or other conditions that change the shape of your uterus or cervix; or your uterus is fairly large or small (the doctor will be able to tell you when you are examined)
- you have already had previous problems with an IUD (for instance the IUD has come out by itself)
- you are unable to have a follow-up check after insertion
Benefits With Using a Hormone-Releasing IUD
- It is a very effective form of contraception
- It is long acting and can stay in place and protect against pregnancy for up to five years
- The hormone-releasing IUD called Mirena® is listed on the PBS, which means that if you have a Medicare card it is subsidised by the government. If you have a Healthcare card you just pay the standard fee for a script at the pharmacy. If you don’t have Medicare, the initial cost of a hormone-releasing IUD is more than for other methods, but it lasts for five years so it can work out to be quite inexpensive
- It is immediately reversible so when it is removed you return to your usual level of fertility
- 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
- If you haven’t had children or if you have only had caesarean deliveries, the IUD may be more difficult to insert
- Women may have irregular bleeding and spotting in the first few months after the hormone-releasing IUD is inserted. Bleeding usually settles down and periods become shorter and lighter. Up to 65% of women end up with no bleeding at all after 12 months of use
- 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
- There is a small chance of getting a pelvic infection (PID) at the time of the IUD insertion. It occurs in about one in every 500 insertions and usually happens in the first 3 weeks after insertion. PID may rarely lead to reduced fertility and problems falling pregnant in some women
- Very rarely the wall of the uterus can be damaged by the process of inserting an IUD, or by the IUD itself, usually at the time of theinsertion. It occurs in about one in every thousand insertions, although the risk of this may be slightly increased in women who are breastfeeding, who have given birth in the past 6 months, or had a previous caesarean section
- The IUD may be pushed out of the uterus into the vagina and can occasionally fall out, without you noticing. This is called ‘expulsion’ and happens in about five out of every 100 women with an IUD. It is most common in the few months after the insertion procedure
- Occasionally a woman becomes pregnant with an IUD in place. This happens in fewer than one in 100 women who have an IUD. The IUD is usually removed although this is associated with a small chance of miscarriage
- If you fall pregnant with an IUD in place there is a small risk that the pregnancy is outside the uterus in the fallopian tubes. This is called an ectopic pregnancy. This is an uncommon complication and less common than amongst women who are not using any contraception
How Do You Get the Hormone-Releasing IUD?
You need to go to a specially trained doctor for an IUD. At a Family Planning clinic you are usually asked to make two visits. On the first visit the doctor will ask you questions 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 probably also be given a script to get the hormone-releasing IUD from a pharmacy before your insertion visit.
On the second visit you will have the IUD inserted. You may be given a local anaesthetic into the cervix before the IUD is inserted, but this is not always needed. Sometimes women are referred to have the IUD inserted with some intravenous sedation, especially if they are very anxious or have not had a vaginal birth.
Your doctor will explain the procedure to you. It takes about 10 minutes and some women may find the experience uncomfortable while others may find it quite painful. You do not have to fast before the procedure, in fact it is a good idea to eat before hand. You may feel faint during or after the insertion and you will probably need to rest for a while before you leave the clinic. You should allow about an hour to be at the clinic.
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 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, see your doctor. You should avoid vaginal sex, tampons, swimming and baths for two days, to reduce the risk of infection.
You will need to go back to the doctor for 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, women may have irregular bleeding and spotting in the first few months after the hormone-releasing IUD 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. You need to go to a doctor or Family Planning clinic to have it taken out. The doctor uses a special instrument 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.
Things To Remember If You Choose a Hormone-Releasing IUD
- Learn to check the string each month after your period to make sure the IUD is still in the right place
- If you have any unusual symptoms including a discharge from your vagina, pain low in your abdomen or deep pain during intercourse, see your doctor straight away
- If you are concerned that you could be pregnant, see your doctor or clinic for a pregnancy test. But remember, you can miss periods with the hormone-releasing IUD
- If you, or your partner, ever have casual sex, or if you have a new sexual partner, use a condom every time until you both have been checked for sexually transmissible infections (STIs)
- Keep a record of the date for replacement because an IUD should not stay in for longer than the recommended time
For More Information
- Contact the Family Planning NSW Talkline on 1300 658 886 or go to Talkline page.
- NRS (for deaf) 133 677
- Or visit your nearest Family Planning clinic