Effects of Two Estradiol/Norgestrel Combinations on the Ovulatory Pattern and on Sex Hormone Binding Globulin Capacity in Women Around Forty Years of Age

Abstract. Thirteen women aged 36—46 years (mean 43) who were seeking contraceptive advice, were monitored for 3 months with basal body temperature (BBT) and were then treated for 3 months with CyclabilR (11 tablets of 2 mg es‐tradiol valerate (E2) followed by 10 tablets of 2 mg E2 + 0.5 mg norgestrel). This treatment was immediately followed by another 3 months with CyclabilR + 2 mg E2. BBT revealed a spontaneous ovulatory rate of 89%. Cyclabil reduced the ovulatory rate, as measured with repeated serum progesterone analyses, to 37%, and Cyclabil + 2 mg E2 resulted in a marked reduction in the number of ovulations (3 %). Both types of hormonal combination resulted in relatively small changes in Sex Hormone Binding Globulin Capacity. It is concluded that the addition of 2 mg E2 to CyclabilR causes a decrease in ovulation rate to such an extent that women using this combination run a relatively small risk of conceiving. One advantage over contraceptive steroids may be that the present combination contains a natural estrogen at a relatively low concentration.