What are they?

IUD stands for intrauterine device, a small plastic or copper contraceptive that is placed into the uterus (womb) by a doctor. It is often called the 'coil' and works by stopping sperm from meeting an egg, or preventing an egg from settling in the womb.

The IUS (intrauterine system) is essentially an IUD containing slow-release progestogen. Both types of device have tiny threads that hang into the top of the vagina - for purposes of checking the device is in place and also removal. 

It takes about 15-20 minutes for a doctor to fit an IUD or IUS and may hurt a little - you may want a local anaesthetic or painkillers. The doctor or nurse should talk to you about the pain beforehand. Once it is fitted, you will need to go back for a check up three to six weeks later.

Benefits:

• Both the IUS and IUD are effective immediately, providing 98-99% protection against pregnancy for three to ten years (depending on which device and brand you choose);
• Doesn't get in the way of sex;
• Easily removed by the doctor, and fertility returns quickly;
• The IUS can help reduce menstrual bleeding.

Drawbacks:

• IUD or IUS devices guard against pregnancy, but not sex infections. Always use a condom as well for maximum protection;
• Both devices can cause menstrual irregularities;
• In rare cases, an IUD or IUS device can slip out of the womb, increasing the risk of pregnancy;
• In the first few weeks after insertion, some women may experience pelvic infection (with IUDs) or breast tenderness and acne (with IUS). All symptoms should be temporary, so see your GP if they persist;
• Risk for some women of pelvic infection (with IUDs).

The IUD is not suitable for:

• Women who have had an ectopic pregnancy;
• Women who have heavy and painful periods;
• Women who have untreated genital infections.

The IUS is not suitable for:

• Patients with certain liver diseases;
• Patients with severe heart or arterial disease;

Updated: 23/04/2010