Caption

Intrauterine device. Artwork of an intrauterine contraceptive device (IUD) in the uterus. The IUD or coil (T-shaped, centre) is a plastic device that is inserted into the uterus (in the blue area) through the vagina (lower centre). A coil of copper wire may be wrapped around the stem to aid the IUD's effectiveness. The string that hangs down into the vagina allows the IUD to be removed easily. The ovaries (oval) are at centre left and right with the one at right sectioned, revealing an egg. IUDs are thought to stop the implantation of fertilized eggs in the uterine wall. The chance of pregnancy is 2-3% per year of use.