In 5 normocyclic women, firstly taking a conventional oral contraceptive, Neogynon (50 mcg EE + 250 mcg levo-norgestrel) for 6 months, the levels of LH, 17 beta-E2 and progesterone did not rise after changeover to a dose-reduced pill, Microgynon 30 (30 mcg EE + 150 mcg levo-norgestrel). This fact indicates maintained central suppression. Examination of the hypothalamic-hypophyseal axis by the Gn-RH test (50 mcg) with Microgynon 30 showed negative results during the first treatment cycle in 13 out of 18 women. In the 6th treatment cycle only 7 Gn-RH non-reactive women were observed and after stimulation with 100 mcg Gn-RH only 5 women remained with negative Gn-RH tests. Of the 20 women who took conventional oral contraceptives over a period of 6 months to 6 years (7 took Eugynon: 50 mcg EE + 500 mcg D,L-norgestrel, 5 Lyndiol: 75 mcg mestranol + 2.5 mg lynoestrenol, 8 Neogynon, only one from the Neogynon group showed a positive result. On the other hand there was a positive reaction in 4 out of 7 women using the two step dose-reduced preparation Sequilar (11 tablets of 50 mcg EE + 50 mct levo-norgestrel and 10 tablets of 50 mcg EE + 125 mcg levo-norgestrel).
PIP: In 5 normocyclic women taking the oral contraceptive (OC) Neogynon (50 mcg ethinyl estradiol [EE] + 250 mcg levonorgestrel), the levels of LH, 17beta-estradiol 2, and progesterone did not rise after changeover to a dose-reduced pill Microgynon 30 (30 mcg EE + 150 mcg levonorgestrel). This fact indicates maintained central suppression. Examination of the hypothalamic-hypophyseal axis by the Gn-RH test (50 mcg) with Microgynon 30 showed negative results during the 1st treatment cycle in 13 of 18 women. In the 6th treatment cycle, only 7 Gn-RH nonreactive women were observed, and after stimulation with 100 mcg Gn-RH, only 5 women remained with negative Gn-RH tests. Of the 20 women who took conventional OCs over a period of 6 months-6 years (7 took Eugynon--50 mcg EE + 500 mcg D'L norgestrel; 5 Lyndiol--75 mcg mestranol + 2.5 mg lynestrenol; 8 Neogynon). Only 1 from the Neogynon showed a positive result. On the other hand, there was a positive reaction in 4 of 7 women using the 2-step dose-reduced preparation Sequilar (11 tablets of 50 mcg EE + 50 mcg levonorgestrel and 10 tablets of 50 mcg EE + 125 mcg levonorgestrel. Our results suggest that preparations with reduced steroid content influence hypophyseal function to a lesser extent, while simultaneously maintaining hypothalamic suppression, than conventional combinations of steroids do. (author's)