Studies of ovarian biopsies from women cyclically treated with the combination ethynodiol diacetate+mestranol alone and together with human menopausal gonadotrophin (Pergonal)+HCG.

To assess Ovulens (1 mg. ethynodiol diacetate and .1 mg. mestranol) effectiveness a group of 39 women (aged 23 to 44) were treated with the drug for periods ranging from 1 to 24 cycles. In the last treatment cycle all women were operated upon and their ovarian function was assessed by direct inspection of the ovaries and by histological examination of ovarian biopsies. In 15 of the 39 women gonadotrophin HP-FSH or HMG (Pergonal) and HCG were administered to induce ovulation. Upon examination no fresh corpus luteum was found in the ovaries of the women treated with the oral contraceptive alone. In the group treated with the contraceptive and gonadotrophins 7 of 15 had functioning corpora lutea. These results demonstrate that Ovulen works as a contraceptive by inhibiting ovulation due to the suppression of pituitary gonadotrophins however a direct effect on the ovary can not be excluded.