An Intrauterine Device (IUD) is a small object that is inserted through the cervix and placed in the uterus to prevent pregnancy. A small string hangs down from the IUD into the upper part of the vagina. The IUD is not noticeable during intercourse. IUDs can last 1-10 years. They work by changing the lining of the uterus and fallopian tubes affecting the movements of eggs and sperm and so that fertilization does not occur. IUDs are 99.2-99.9% effective as birth control. They do not protect against sexually transmitted infections, including HIV/AIDS.

An IUD is usually inserted during a menstrual period when the cervix is slightly open and pregnancy is least likely. It may be inserted at any time, however. The procedure for insertion takes about 5-15 minutes. Most women feel cramping during and after insertion. Ibuprofen can help relieve cramping.

It is recommended that women check their IUD after each period. A shorter than normal string can be a warning sign of an imbedded IUD. Missing strings may mean that the IUD was expelled. If the string is missing, call the clinic and use a backup method of birth control.

There are two types of IUDs available: ParaGard and Mirena. The ParaGard has a tiny copper wire wrapped around the plastic body and should not be used by anyone who is allergic to copper. The Mirena releases small amounts of a synthetic progesterone hormone. The hormone was added to attempt to decrease the bleeding and cramping that some women have with the IUD.

Both the ParaGard and the Mirena IUDs can cause longer, heavier, and more painful menstrual periods, but this is much less common with the Mirena. The increased blood flow may cause anemia. Spotting may occur without serious cause or as a sign of infection.

There are risks associated with getting an IUD.  Getting any vaginal infection while using an IUD can increase the risk of developing a serious pelvic infection. This can result in a loss of fertility. For this reason, women need to assess their own risk for infection.

Piercing or perforation of the uterine wall may occur during insertion of the IUD. Over time, an IUD may become imbedded in the uterine wall. An Imbedded IUD is still effective, but it can be painful and may need to be removed. There is a risk of surgery and/or sterility if an IUD becomes imbedded.