[Antigestagens]

Recently potent 19-norprogestin derivatives of the RU 486-type were developed. Acting at the receptor level, these steroids are considered a major breakthrough in steroid endocrinology. Clinical studies indicate their potential use in fertility control. Besides biochemical, pharmacological and clinical aspects of the antiprogestins, the ultimate role in the therapeutic management of certain endometrial and breast cancers, endometriosis as well as induction of labour at term are discussed.