The invention relates to 15,16-methylene-17-(1′-propenyl)-17-3′-oxidoestra-4-en-3-one derivatives with the general chemical formula I, where the Z, R4, R6a, R6b, R7 and R18 have the meanings stated in claim 1, and solvates, hydrates and salts thereof, including all crystal modifications and all stereoisomers of these compounds. The invention also relates to the use of these derivatives for the production of a drug for oral contraception and for the treatment of pre-, peri- and postmenopausal problems and drugs which contain such derivatives, in particular use in the aforesaid indications. The derivatives according to the invention have a progestational and in preferable cases also an antimineralcorticoid and neutral to slight androgenic activity.