宫内避孕器是一种作用于人体局部,对机体功能扰乱较小的避孕工具,具有安全、有效、简便及经济等特点,作为计划生育重要措施之一,已在我国及世界各地广泛使用。但目前所用的宫内避孕器还有不足之处,主要是脱落、带环受孕、腹痛、出血及月经过多等缺点。过去曾不断用各种材料制造了许多不同类型大小的避孕器,但这些铁 Intrauterine device is a kind of contraceptive which acts on the human body and has less disturbance to the body function. It is safe, effective, simple and economical. As one of the important measures of family planning, IUD is widely used in our country and around the world. However, there are still inadequacies in the intrauterine devices currently used, which are mainly the disadvantages of falling off, banding, abdominal pain, bleeding and menorrhagia. In the past, many different types and sizes of contraceptives have been continuously made of various materials, but these iron