This month's Women's Health Magazine has a feature on IUDs, calling them "your doctor's favorite birth control." IUDs are out of favor here in the US, mainly due to the tragedy over the Dalkon Shield. This specific IUD was popular in the 1970s, however, it was modified after FDA approval (if I remember the cases correctly), and caused thousands of health problems, including hysterectomies and death. IUDs are much safer now. There are basically two types - the copper type and the hormonal type. It is a reversible form of birth control, and must be implanted/removed by a doctor. There's more information both in the magazine article, and at your doctor's office.