An intrauterine device (IUD), also known as the contraceptive coil, is a small T-shaped plastic and copper device that's put into the uterus to prevent pregnancy.
It works by releasing copper into the uterus, altering the cervical mucus, making it more difficult for the sperm to travel to the egg and survive. The coil also prevents a fertilised egg from implanting to the uterine lining.
The coil insertion is carried out by a specially trained medical professional and, once in place, it can be left alone and you do not have to do anything else. If inserted correctly, it is more than 99% effective as a contraceptive and can last for between five and ten years, depending on the type of IUD. If you are aged 40 or over at the time of coil insertion, the IUD can be left in place until you reach menopause or until you no longer need contraception.
An IUD can be removed by a medical professional at any time during your cycle and you will be able to get pregnant immediately. Having an IUD does not affect your fertility.