Intrauterine System (IUS)

How effective?

Over 99% effective. Less than 1 woman in 100 will get pregnant in a year

How it works

A small plastic device, which releases progestogen, inserted into the uterus. It thickens the cervical mucus to prevent fertilisation, thins the lining of the uterus to prevent an egg implanting and may stop ovulation

Advantages

Works for five years but can be taken out at any time. Periods will be much lighter, shorter and usually less painful. You don’t have to think about contraception as long as the IUS is in place. When the IUS is removed the normal level of fertility will return

Disadvantages

Irregular light bleeding between periods is common for the first three months or longer. Maybe temporary side effects such as headache, spotty skin and breast tenderness. Very small chance of getting an infection during the first three weeks after insertion

Comments

Women are taught to check the IUS is in place by feeling the threads high in their vagina. Very useful for women with very heavy and/or painful periods. A check for any existing infection is usually advised before an IUS is fitted