IUS

Standing for IntraUterine System

What is it?

The IUS is similar to the IUD, as it is a small plastic device which is placed in the womb to prevent pregnancy. However, the IUS also contains the hormone progestogen. The IUS is a long-term contraceptive which can be left in place for up to 5 years.

How does it work?

The progestogen released by the IUS works in several ways to prevent a woman from getting pregnant; firstly it thickens cervical mucous to prevent sperm from being able to reach an egg, secondly it thins the lining of the womb so that if an egg was fertilized it would not be able to implant, and lastly for some women it may stop eggs from being released (ovulation).

The IUS itself also helps prevent sperm from reaching an egg and any fertilized eggs from implanting in the womb, by creating a hostile environment in the womb.

How effective is it?

The IUS is over 99% effective at preventing pregnancy.

What are the advantages?

It can be fitted at any time, you don’t have to remember to take anything and it does not interrupt sex. Also, your periods will probably be shorter and lighter, and for some women may stop completely. However, your periods and fertility will return quickly if the IUS is removed.

What are the downsides?

When you have the IUS fitted you may experience side effects, such as breast tenderness, spotty skin and headaches. Also, you may not have regular bleeds (periods), which some women find annoying or worrying.

There is a small chance that you could develop an infection after having the IUS fitted, or, very rarely, that having the IUS fitted may perforate your womb. This is not likely if the doctor or nurse fitting your IUS has lots of experience.

Things to bear in mind

It needs to be fitted by a specially trained doctor or nurse, and having it fitted may be uncomfortable or even a little painful. Also, if you have picked up a sexually transmitted infection from unprotected sex and have an IUS fitted you could get a pelvic infection.

Most importantly, the IUS does not provide any protection against HIV or sexually transmitted infections like a condom does.

Where can I get it from and how much does it cost?

The IUS is available free on the NHS. You can only get it on prescription from a doctor. This can be your GP, another GP who you have registered with for family planning services, or a doctor at a family planning or young person’s clinic.