An intrauterine device (IUD) is a form of birth control in which a T-shaped, plastic device is placed by a doctor or health professional in the uterus of a woman. While over 99% effective at preventing pregnancies, IUDs do not protect against STIs, so always use a condom if the STI status of your partner is unknown. There are two IUDs available in the US: ParaGard releases copper ions and is effective for up to 12 years, while Mirena releases small amounts of hormones and is effective for five years. IUDs work by affecting the movement of sperm, thereby preventing the joining of sperm and eggs, while also changing the lining of the uterus and making it more difficult for fertilize eggs to implant themselves. The hormones in Mirena further work to prevent pregnancy by ensuring that the woman does not ovulate (or release eggs) and building a mucus barrier at the woman’s cervix which reduces the likelihood sperm will actually enter the uterus. The ParaGard IUD can also be used as a form of emergency contraception, similar to the “morning after” pill, and is most effective if placed in the uterus within five days of unprotected intercourse. IUDs should not be used if you have a pelvic infection, cancer in the reproductive organs or breasts (for Mirena, the hormone IUD), or Wilson’s disease, a condition where the body cannot rid itself of copper (for ParaGard). While the initial cost of an IUD is more than that of other forms of birth control, the long term efficacy of these devices make them one of the least expensive birth control options in the long run. IUDs must be checked regularly by a health care provider to ensure that they have not slipped out of the uterus (thus rendering them an ineffective form of birth control) or, in rare situations, developed an infection after the IUD was inserted.
For more information on IUDs, visit http://www.plannedparenthood.org/health-topics/birth-control/iud-4245.htm or ask a Sexpert! Both ParaGard and Mirena are available at Dick’s House, so if you are seriously interested, you can make an appointment to see if an IUD might be a good choice for you.