An intrauterine device (IUD) is a t-shaped piece of flexible plastic that is inserted into the uterus in order to prevent pregnancy.  This t-shaped piece of plastic often contains copper or a synthetic hormone that prevents pregnancy by altering the cervical mucus inside of the uterus that either kills sperm or makes them immobile.  It also changes the lining of the uterus to prevent implantation should fertilization occur.  It is sometimes also called an “Intrauterine Contraceptive Device.”  (IUCD)