[The effect of different types of oral contraceptives upon ovarian function (author's transl)].

An investigation on the influence of different types of oral contraceptives upon serum gonadotropins, estradiol and progesterone was carried out in 10 volunteers. The effect of a change from a normophasic type preparation to a sequential preparation (Ovanon and Kombiquens) and from a combined preparation to a minipill (Neogynon and Exlutona) was studied. Two new 3-phase step-up preparations were also tested. Ovulation was inhibited in each case as the preovulatory LH-peak and the subsequent rise of serum progesterone were found to be missing. The basal LH- and FSH-secretion and serum estradiol were demonstrated to be significantly diminished in the volunteers taking combined and sequential preparations. The release of gonadotropines was not inhibited as much when the 3-phase step-up preparations (SHB 261 AB and SHB 264 AB) were used. When Exlutona was taken, the basal LH-secretion was lower than during the pre- and postovulatory phase of the normal cycle, but follicular development did not appear to be inhibited much as both FSH and estradiol were found to be in the normal range.