What is an IUS?
An IUS is a small, T-shaped device that is placed in a woman’s uterus (womb). An IUS is made of flexible plastic which contains a slow-releasing hormone (Levonorgestrel). It has two soft threads on the end. These thin threads hang through the opening at the entrance of the womb (cervix) into the top of the vagina.
There are three types of IUS available: Mirena which lasts 8 years, Kyleena which lasts five years, and Jaydess which lasts three years.
How does it work?
An IUS works by changing the conditions in the womb and cervix. These changes prevent sperm fertilising an egg and may also prevent a fertilised egg implanting in the womb.
How effective is it?
The IUS is more than 99% effective. This means less than one woman in every 100 women who use the IUS will get pregnant in a year. The IUS is a long-acting reversible contraceptive. All long-acting methods are very effective because while they are being used you do not have to remember to take or use contraception.
Where can I get an IUS fitted?
You can get an IUS from a family planning clinic or a GP. Some doctors will fit an IUS, but not all.
The IFPA’s clinics in Dublin city centre and Tallaght provide long-acting contraceptive services.
When and how is it fitted?
An IUS can be fitted at any time in your menstrual cycle if it is certain you are not pregnant. This means you must have been using a reliable method of contraception for at least three weeks before the insertion. This can be arranged at the first visit. An internal examination is carried out before the IUS is inserted. The insertion visit takes approximately 15-20 minutes. Insertion can be uncomfortable or painful for some women. Some women experience a period-type pain and light bleeding for a few days afterwards. Painkillers are provided for this.
How often do I need to see the doctor?
You should have a check-up 4 to 6 weeks after insertion. After this, if you have no problems and check threads monthly, you do not need routine visits. You should contact your doctor or family planning clinic if you have any concerns such as; pain in the pelvic area, unusual vaginal discharge, heavy bleeding, suspect pregnancy, feel you may have contracted an STI or you wish to have the IUS removed.
When and how is the IUS removed?
A trained doctor can take the IUS out at any time, by gently pulling on the threads.
If you are not going to have another IUS inserted, and don’t wish to become pregnant, an extra contraceptive method, such as condoms should be used for seven days once the IUS is removed. Sperm can live for up to seven days inside a body and could cause pregnancy once the IUS is removed. Normal fertility returns as soon as the IUS is taken out. If you wish to have another IUS it can be inserted directly after the old IUS has been removed.
What if I become pregnant while I am using an IUS?
The IUS is a highly effective method of contraception, so it is unlikely that you will become pregnant. If you become pregnant there is a small possibility of it being an ectopic pregnancy. This is when the egg is fertilised outside the womb, usually in the Fallopian tube, and starts to grow. This is rare but serious. Consult a doctor immediately if you have any lower abdominal pain and feel that you may be pregnant.
If you become pregnant with an IUS in place your doctor will usually remove the device, if possible. While there is a risk of miscarriage following the removal of the device, leaving it in could cause miscarriage later in the pregnancy or cause labour to start early.
What are the risks?
It is not common but there is a risk that an IUS might perforate the womb during insertion. This may cause pain but there are often no symptoms. If this happens the IUS may have to be surgically removed. The risk of perforation is very low when the IUS is fitted by an experienced doctor. There is a small risk of pelvic infection in the first three weeks after insertion. Again, for this reason, the IFPA recommends a test for infection beforehand. The warning signs of pelvic infection are pain during or after intercourse, pain in the lower abdomen or unusual vaginal discharge, especially if you have a fever. Infection can lead to infertility. See your doctor.
The IUS may be pushed out by the uterus (expulsion). This is most likely to occur in the first three months. It may only be partly expelled or may pass out of the vagina with blood during a period. As such it may not be obvious. This is why a doctor will ask a patient to check their IUS threads each month.
Can an IUS be used as emergency contraception?
No, only copper IUCDs can be used as emergency contraception.
Will an IUS protect me against sexually transmitted infections?
No, the IUS does not protect against STIs, so you may have to use a condom as well.
Will the IUS be affected if I am on other medication?
No, your contraception will not be affected by any other medication.
How long does the IUS last for?
The IUS acts as an effective method of contraception for 3 – 6 years depending on the type used.
Can I have another pregnancy after using the IUS?
Yes, fertility returns to normal immediately after the removal of an IUS device.
Will an IUS affect my periods?
There may be frequent irregular bleeding in the first 3-6 months after an IUS has been inserted. Over time periods become lighter and shorter and some women may have no periods at all.
Can I use tampons?
You may be asked not to use tampons immediately after insertion, but longer term there is no problem.
Can anyone use an IUS?
Most women can, including those who have never had a child. However the doctor will need to check your medical history before deciding if it is suitable for you
What if I just had a baby?
If you have just had a baby, fitting of an IUS is usually deferred until at least eight to twelve weeks after the birth. Another contraceptive method will need to be used until then. It can also be put in within 48 hours of giving birth. An IUS can be used safely while breastfeeding and will not affect milk supply.
Can I use an IUS after an abortion or miscarriage?
An IUS can be put in immediately after a miscarriage or abortion if you were pregnant for less than 24 weeks.