[The efficacy of gestoden (delta 15-d-norgestrel) as ovulation inhibitor (author's transl)].

Two single-phase combined low-dosage oral contraceptive preparations were tested with respect to their effects on functional parameters of the menstrual cycle. Twenty young women with a normal biphasic menstrual cycle took part in this random study. Evaluation of cervical function, consistency and crystallisation ability of the cervical mucous and of the karyopyknosis index as well as radioimmunoassay of the serum levels of LH, FSH, HPRL, 17-beta-oestradiol and progesterone were carried out consecutively as from the 8th day over the duration of one control cycle and one in which contraceptive as administered. Preparation I (SH D 356 A) contained 75 micrograms delta 15-d-norgestrel (Gestoden) + 30 micrograms ethinyloestradiol. Whilst preparation II (SH D 356 B) contained 75 micrograms d-norgestrel + 30 micrograms ethinyloestradiol. Both substances successfully inhibited ovulation, whereby the former achieved a markedly greater suppression of function with regard to all parameters and, yet good menstrual cycle control was maintained. Hence, gestoden enables the content of active components in oral contraceptives to be reduced even further without detracting from the safety of the technique.