New combined oral contraceptive with incremental progestogen dosage regimen.

Abstract

In a study of 506 women, 272 took a total of 2124 cycles of combined preparations of norgestrel and 234 women took a total of 2002 cycles of a combined contraceptive with incremental progestogen doses, in which the total D-norgestrel was 1800 g as opposed to 5250 g in the combined preparation. The step-up preparation group had a similar rate of side effects as the combined preparation group; however, women using the step-up preparation had significantly diminished intermenstrual bleeding after the 6th month of use. The step-up regimen has not induced any cases of endometrial hyperplasia but does have an inhibiting effect on endometrial proliferation in the 1st half of the cycle. The step-up preparation has similar effects on the hypothalamo-hypophysial-ovarian axis as the combined pill. The step-up preparation appears to inhibit ovulation from the 1st cycle as indicated by the absence of LH and FSH midcycle peaks and the low 17 beta-estradiol levels in the 2nd half of the cycle; therefore, the step-up preparation should be classified as a new combined, not sequential, oral contraceptive.