title: [Clinical study of three types of IUD].
mesh_terms: D000328:Adult; D002986:Clinical Trials as Topic; D005260:Female; D006801:Humans; D007433:Intrauterine Device Expulsion; D007434:Intrauterine Devices; D007435:Intrauterine Devices, Copper; D009757:Nylons; D011247:Pregnancy; D011275:Pregnancy, Unwanted; D011897:Random Allocation
chemical_list: D009757:Nylons