CYCLIC AND STEP‐UP ADMINISTRATION OF ETHYNODIOL DIACETATE AS AN ORAL CONTRACEPTIVE

Abstract

A study involving cyclic and step-up administration of ethynodiol diacetate as an oral contraceptive was presented. The step-up group received 23 tablets of .1 mg mestranol plus ethynodiol diacetate. The sequential formulation consisted of 16 tablets of .1 mg mestranol alone and 7 tablets of .1 mg mestranol plus .5 mg ethynodiol diacetate. Both preparations had 5 placebo tablets to complete the 28-tablet sequence. No pregnancy occurred among 294 women using the step-up progestogen regime for 2578 cycles and 1 pregnancy occurred in the series of 290 women who completed 2851 cycles of the sequential regime. Both series showed a low incidence of side effects. Vaginal smear studies confirmed that these preparations have a higher estrogen activity (pyknotic index) than previously studied compounds containing higher concentrations of ethynodiol diacetate.