What is the intrauterine device (IUD)?
An intrauterine device (IUD) is a highly effective and reliable method of contraception that lasts for 5 years or more.
They are small devices that are placed inside the uterus (womb) to prevent pregnancy. There are 2 types of IUD — the hormonal IUD and the copper IUD.
You need a prescription to get an IUD. It needs to be put in place by a doctor or nurse.
How does the IUD work?
The hormonal IUD
The hormonal IUD is made of plastic and releases a hormone. There are 2 types of hormonal IUDs available in Australia: Mirena and Kyleena, both of which can be used for up to 5 years. They slowly release a progestogen hormone called levonorgestrel. Kyleena contains a lower dose of this hormone than Mirena. The hormone thickens the mucus at the entrance to the uterus so sperm cannot get through, and thins the lining of the uterus, making it hard for a fertilised egg to take hold. This is similar to the way in which the mini pill and the contraceptive implant work.
The copper IUD
The copper IUD is made of copper and plastic, and does not release a hormone. There are 2 copper IUDs available in Australia. Multiload lasts for up to 5 years and the Copper T (or TT380R) lasts for up to 10 years. The copper IUD works by:
- making it harder for sperm to reach and fertilise an egg
- changing the lining of the uterus so that if an egg was fertilised, it still wouldn't be able to attach and develop
Copper is toxic to sperm, so the copper IUD can also be used as an emergency contraceptive within 5 days of unprotected sex.
How effective is the IUD?
The IUD works very well if inserted properly, and is one of the most effective reversible methods of contraception available.
If 100 women use an IUD for a year, fewer than 1 will become pregnant.
What are the advantages and disadvantages of the IUD?
Both types of IUD offer several benefits, which include being:
- extremely good at preventing pregnancy
- easy to use and maintain
- long-lasting and cost-effective
- immediately reversible if you decide you want to get pregnant
The hormonal IUD also makes periods lighter and less painful. Sometimes they stop altogether.
The main disadvantages of IUDs include:
- a small risk of problems after insertion, such as pelvic infection
- they can move out of place
- Mirena can cause side effects such as irregular bleeding and sore breasts
- copper IUDs can initially make periods heavier and more painful
What is the process for IUD removal?
Although IUDs provide protection for many years, they can be removed earlier. It is a quick procedure, in which a doctor gently pulls on the string, and the IUD's arms fold up so it slips out. Some women find it uncomfortable while others don't feel very much.
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Last reviewed: March 2021