intrauterine device (IUD) [L, intra + uterus, womb; Fr, devise] , (Informal) a contraceptive device, consisting of a bent strip of radiopaque plastic with a fine monofilament tail. The addition of copper wire and/or bands increases the effectiveness. Progesterone-filled IUDs are also available. The mechanism of action is not known. Insertion into the cervix is performed during or just after menstruation when the cervix is slightly open and menstruation assures that a pregnancy does not exist. The tail string of the IUD is left projecting a few centimeters from the cervix. By feeling the string with her finger at least once each menstrual cycle the wearer can be sure the device is in place. The string also provides a hold for removing the IUD. The rate of failure for the IUD method of contraception is approximately one to five unplanned pregnancies in 100 women using the device for 1 year. IUDs can cause complications; the most serious is pelvic inflammatory disease. When such infections occur in pregnancy, they may be overwhelming and lethal; therefore the IUD is removed if pregnancy is suspected. Some other complications are cervicitis, perforation of the uterus, salpingitis that causes sterility, ectopic pregnancy, abortion, embedding of the device in the wall of the uterus, endometritis, bleeding, pain, cramping, undetected expulsion, and irritation of the penis. Also called coil, loop, intrauterine contraceptive device.
