Over the last few decades, the number of contraceptive methods available for women has drastically increased. There are now 15 different options to choose from, including barrier methods (like condoms), hormonal methods (including pills, patches, injections and implants) and IUDs (otherwise known as intrauterine devices).
The Mirena is an intrauterine system (IUS) or hormone coil. This small T shaped device is inserted into the uterus (womb) and releases levonorgestrel (a type of progesterone) into the womb.
What is the IUS used for and what are the benefits?
The Mirena has many uses.
- It is one of the most effective forms of reversible contraception (providing contraception for up to 5 years and sometimes longer). It is more effective than female sterilisation. Once inserted, you do not have to think about contraception every day or each time you have sex. It can be removed at any time and, if you wish to conceive, your fertility returns to normal quickly.
- It can be used in the treatment of heavy menstrual bleeding. After an initial settling-in period, it can make your periods shorter and lighter.
- It can be used as part of hormone replacement therapy for women going through the menopause.
- It can also be useful for the treatment of small fibroids and, in some cases, of endometriosis
Is Mirena right for me?
You should discuss Mirena with your healthcare provider if you are considering having one inserted as it is not appropriate for certain women such as those who have or have had breast cancer, uterine or cervical cancer, have a pelvic infection or uterine abnormalities, or in those women who have unexplained vaginal bleeding.
A Mirena can only be fitted by a specially trained health care professional and the insertion procedure lasts a few minutes. You may experience some discomfort with cramps similar to period pains. Some women find that their usual painkillers help.
What are the risks of Mirena?
Some minor or nuisance side effects such as headaches, tender breasts, acne breakouts and mood changes can occur and these settle with time as your body gets used to the Mirena. Irregular bleeding and spotting is common and may be experienced in the first few months, and, by the end of the first year of use, some women find that their periods stop altogether.
There are very few more serious risks associated with the Mirena. These risks will be explained thoroughly by your doctor.
- Occasionally during insertion, the IUS can make a small hole in the womb called a perforation. This is very rare and happens 1-2 times for every 1000 times an IUS is fitted. If perforation occurs, an operation may be needed to remove the IUS.
- Expulsion or rejection may occur once in every 20 fits and the IUS will simply fall out of the womb. You can keep an eye on the placement of your IUS and your doctor or nurse will teach you how to check it.
- Rarely, cysts (fluid filled sacs) can appear on the ovaries, but these not dangerous and usually go away on their own.
- IUDs do not protect against sexually transmitted infections and you will need to use condoms as well if you are worried about this. There is a small chance of developing PID (pelvic inflammatory disease) which is a serious pelvic infection that is usually transmitted sexually. The risk of developing PID increases if you or your partner have sex with other people. The risk of infection is higher soon after the IUS is fitted.
Before having Mirena fitted, make sure you speak to your healthcare provider about the advantages, disadvantages and risks, so you can understand if the device is right for you and your needs.