Modulation of ovarian function by a combined oral
contraceptive containing 30 µg ethinyl estradiol and 2 mg chlormadinone acetate
J Spona, W
Feichtinger, N Binder, K Höschen
Czerningasse 10, 1020 Vienna, Austria, Wunschbabyzentrum, 1020,
Austria, and Gruenenthal GmbH, 52078 Aachen, Germany
The
aim of this single-center, open, uncontrolled, multiple dosing phase II study
was to investigate the modulation of ovarian function, endometrial thickness and
cervical function by a combined oral contraceptive (COC) containing 30 µg
ethinyl estradiol and 2 mg chlormadinone acetate during 3 medication cycles. 33
healthy women, aged between 19 and 35 years were evaluated and constituted the
per protocol set (PPS). Measurements of parameters describing ovarian, cervical
and endometrial function were performed every other day during the study. All
subjects ovulated in the pre-treatment cycle. During the 3 medication cycles no
ovulation was observed in the PPS. Residual ovarian activity was seen in 1 of 30
subjects (3.3%), 5 of 28 subjects (17.9%) and 6 of 25 subjects (24%) in
medication cycles 1, 2 and 3, respectively. In total, residual ovarian activity
according to Hoogland and Skouby (1993) was observed in 12 of 83 (14.5%)
medication cycles. In only 1 of 83 (1.2%) medication cycles a luteinized
unruptured follicle-like structure was found. Serum sex hormone concentrations,
endometrium thickness and ovarian function were effectively suppressed during
treatment and returned to baseline levels during the post-treatment phase. The
results of the present investigation indicate that the modulatory effects on
ovarian function of the monophasic COC containing 30 µg ethinyl estradiol and 2
mg chlormadinone acetate lead to adequate suppression of ovarian activity and
effective inhibition of ovulation.