Intrauterine devices, commonly referred to as IUDs, are small, plastic objects that are inserted into the uterus. The two IUDs are the ParaGard and Mirena (I Figure 10.7). The ParaGard is a plastic T with a copper wire wrapped around its stem and copper sleeves on the side arms. Mirena is a polyethylene T with a cylinder containing progestin (Akert, 2003). The IUDs have fine plastic threads attached; the threads are designed to hang slightly out of the cervix into the vagina.
The IUD is the most common reversible contraceptive used by women in the developing world (Salem, 2006). About 6% of women in the United States use the IUD, and those who do use this method are usually very pleased with it, as indicated by its 80% continuation rate (how many women who start using a method are still using it one year later; Nordqvist, 2011). This is a higher continuation rate than for pills, patches, rings, condoms, or Depo-Provera (Hatcher, 2006). The IUD and implant are the only long-acting reversible contraceptives (Thompson et al., 2011). In addition, serious complications are rare with the modern IUD (Campbell et al., 2007) and are described in ■ Table 10.6.