INHIBITION OF OVULATION BY AN ORAL-CONTRACEPTIVE CONTAINING 100 MU-G LEVONORGESTREL IN COMBINATION WITH 20 MU-G ETHINYLESTRADIOL

Twenty-lour healthy female volunteers with normal ovulatory cycles, ag ed between 20 and 34 years (27.5 +/- 4.3), were included in a single-c enter, non-comparative study to investigate the effect on inhibition o f ovulation of an oral contraceptive containing 20 mu g ethinylestradi ol in combination with 100 mu g levonorgestrel. At baseline, during th ree treatment cycles and post-treatment, ultrasonography was used to e xamine the ovaries, to measure follicular size, and to measure the thi ckness of the endometrium. Serum levels of LH, FSH, estradiol, progest erone, total testosterone, free testosterone, SHBG, and CBG were also measured. Compared with treatment cycle 1, an increase in residual ova rian activity (follicle grades 4-5) was observed in cycles 2 and 3. Me an levels of LH, FSH, 17 beta-estradiol and progesterone remained supp ressed during treatment. No escape ovulation was observed during the t reatment phase of the study and there were no pregnancies. Ovulation w as noted to return rapidly in the posttreatment cycle. Subjective and objective tolerance of the present regimen was noted to be good. Resul ts indicate that the monophasic oral contraceptive containing 100 mu g levonorgestrel combined with 20 mu g ethinylestradiol effectively inh ibits ovulation, providing adequate suppression of ovarian activity. ( C) 1996 Elsevier Science Inc.