An intrauterine device (IUD) is a plastic or copper T-shaped device the gynaecologist places in the uterus. It is one of the most effective methods to prevent pregnancy. Once in place, it stays within the uterine cavity until the patient requests its removal. The IUD has a cord attached to the end so that women can make sure the device is in place. The IUD prevents the sperm from getting into the egg by changing the lining of the uterus. Among its advantages in addition to its effectiveness, is the fact that it is cheap, can prevent pregnancy between 5 and 10 years, it begins to work very quickly, and the woman does not feel it in her body, so it does not cause discomfort.