宫内节育器(IUD)易于设计,成本低,不需要象药物那样严格控制,因而有数十种形态结构不同的宫内节育器在世界各地应用,还有许多正在试验阶段。过去曾使用过的风筝多边形、弓型、盾形、卷边螺旋、M型、乳胶叶等,目前广泛使用的有蛇型、卷边T型、上海V型和太田型等。有一些在设计方面进行了轻微改革后,做为活性药物的载正体进行试验。在六十和七十年代初期,IUD研究的主要目的是进一步了解作用机制为提高避孕效果提供理论基础。当时很少强调如何减少脱落或出血,今天对IUD设计的主要要求是要防止影响继续使用的副 IUDs are easy to design, low cost and do not need to be as tightly controlled as drugs, so dozens of IUDs with different morphological configurations are used around the world and many are in the experimental phase. Kite polygons, bow type, shield type, curling spirals, M type, latex leaves, etc. have been used in the past. Currently there are Snake type, Curling type T, Shanghai V type and Ota type. Some have been slightly modified in design and tested as active carriers. In the 1960s and early 1970s, the main purpose of the IUD study was to further understand the mechanisms of action that provide the rationale for improving contraceptive effectiveness. At that time, it was seldom emphasized how to reduce shedding or bleeding. The main requirement of IUD design today is to prevent the vice