J. Spona et al., INHIBITION OF OVULATION BY AN ORAL-CONTRACEPTIVE CONTAINING 100 MU-G LEVONORGESTREL IN COMBINATION WITH 20 MU-G ETHINYLESTRADIOL, Contraception, 54(5), 1996, pp. 299-304
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.