There are two types of contraceptive coil, one that uses hormones and one that doesn’t. This page is about the hormonal coil (IUS), click here for information and advice about the copper coil (IUD).
A hormonal IUS or intrauterine system is a small plastic t-shaped device with a sleeve that releases a low dose of a progesterone hormone into your uterus (womb). It has two threads that hang down to enable you to check that it is in place and to allow your doctor to remove it at a later date.
The IUS is also known as the hormonal coil. It stops you from getting pregnant by thickening your cervical discharge, by thinning the lining of your womb and occasionally by preventing an egg from being released (ovulation). There are are 4 different types which release a different dose of hormone: Jaydess which lasts 3 years and is the lowest dose, Kyleena which has a slightly higher dose of hormone but lasts 5 years, Levosert which has a slightly higher dose again and is licensed for 4 years and Mirena which has the same dose but is licensed for 5 years.
IUS for HRT use:
The Mirena IUS is the only hormonal coil that is licensed for use as HRT. It can be used, in conjunction with oestrogen gel, patches or tablets, as the progesterone component of combined HRT regimens. If using the Mirena for this purpose it can only be used up to 5 years maximum no matter how old you are. In this situation therefore, the Mirena must be refitted by 5 years. If the Mirena is removed and not refitted the oestrogen only HRT must be changed to a combined regimen. You should inform us if you are using your Mirena for this purpose.
How effective is the hormonal IUS?
A hormonal IUS is 99% effective at preventing pregnancy and can last for 3 to 5 years depending on the type. If it is fitted at the age of 45 years it can last up to 10 years for contraception purposes (but only for 5 years if being used as part of an HRT regimen- see previous section). It starts working 7 days after it is fitted and your fertility will return to normal as soon as it is removed. Occasionally, the IUS can be pushed out by your uterus, or it can move which could affect how it works. This doesn’t happen very often and staff at your Devon Sexual Health clinic will show you how to check so you know it’s in the right place
Are there any side effects?
Some women may experience some spotting or cramps for a number of days following insertion of an IUS. Your periods may initially be quite erratic as the lining of the womb gets thinner, and you may also experience spotting and bleeding for a few weeks or possibly longer. This nearly always settles and you will eventually have very light bleeding or no bleeds at all. There is also a small chance of infection especially during the first 20 days, so if you notice any unusual vaginal discharge or pain then please come back and see us as soon as possible.
The IUS does release a small amount of hormone. This is released into the womb and only a very small amount, if any, is absorbed into the bloodstream. You may notice some breast tenderness after it is first inserted or before a period and some acne or mood changes initially however these should settle and many women say it “evens out ” their moods. There does not seem to be any difference in the hormonal side effects of the different types of IUS.
The hormonal IUS is an extremely effective form of contraception and it’s very unlikely that you will get pregnant. If you do, there is a slightly increased chance that it will result in an ectopic pregnancy.
It’s also important to remember that an IUS cannot prevent you from getting a sexually transmitted infection. If you have a new partner or are unsure of your partner’s sexual history, you should still come in for a check-up
Who can use a hormonal IUS?
Most women can use the hormonal IUS, including those who are HIV positive. It is especially popular with women who have heavy periods as it can make them lighter or stop them altogether. When you come in and see us, we will ask about your medical history and whether you have had any illnesses or complications just to check if the IUS is suitable for you. If you are already pregnant, have problems with your uterus or cervix [link] or have an untreated STI then we may advise you about other methods of contraception. Everyone’s different so please come in and have a chat.
Where can I get a hormonal IUS?
You can get an IUS fitted at any of our Devon Sexual Health clinics. Some GP practices also offer coil fitting. An IUS can only be fitted by a specially trained doctor or nurse.
What happens when you get an IUS fitted?
You need to book an appointment to see a contraceptive nurse or doctor. They will ask you some questions about your health and then will give you a quick examination to check the size and position of your uterus. Sometimes they will also check for any STIs. Inserting the IUS takes around 5 minutes and can be a little uncomfortable. Don’t worry, the doctor or nurse will talk you through this beforehand and may offer you a local anaesthetic if needed. They may be able to fit the IUS at this consultation or they will bring you back for the fitting at a later date. The appointment will last for approximately 30 minutes.
If you decide to have it removed, you need to visit one of our clinics. A specially trained doctor or nurse will remove it and will give you advice about other forms of contraception you could use instead. Your fertility will return as soon as the IUS is removed. You need to make sure that you have used additional contraception or avoided sex for 7 days before you have the IUS removed, otherwise you could still get pregnant.
Pros & Cons
- It lasts for 3-5 years and will lighten or stop your periods.
- It is over 99% effective
- You can’t forget to take it and it does not interfere with sex.
- It can cause erratic bleeding
- It doesn’t protect you from STIs
- You have to book an appointment to have one fitted (although this only takes 30 minutes)