Intrauterine system (IUS)

What it is?

Small plastic T-shaped device which releases the hormone progestogen. It is fitted into the womb by a doctor or nurse.

How it works?

Stops sperm meeting an egg or may stop an egg implanting in the womb.

Advantages

Does not interrupt sex. Works for approximately five years. Periods may be lighter.

Disadvantages

Does not protect against sexually transmitted infections (STIs). Can cause irregular bleeding at first. Can cause temporary side effects such as skin problems or breast tenderness.

How effective is it?

The IUS is 99% effective. This means that 1 in every 100 women who use an IUS will get pregnant each year.

What makes it less effective?

If the IUS moves out of place it will be less effective. Regular check-ups are important.

Can anyone use this method?

The IUS is not suitable for all women. A doctor or nurse will need to know about a woman's medical history and any illnesses suffered by immediate members of her family, to find out if there are any medical reasons why it might not be suitable. It is not usually a first choice of contraceptive method for women who have not had children.

Services