Ovarian activity in women taking an oral contraceptive containing 20 microg ethinyl estradiol and 150 microg desogestrel: effects of low estrogen doses during the hormone-free interval.
OBJECTIVE
We assessed the effect of low ethinyl estradiol doses given during the nominally hormone-free interval of the Mircette (brand of desogestrel/ethinyl estradiol and ethinyl estradiol) contraceptive regimen on ovarian activity.


METHODS
In a randomized, double-blind study, healthy women received 150 microg desogestrel and 20 microg ethinyl estradiol for 21 days followed by either placebo for 7 days (Mircette/placebo; N = 24) or placebo for 2 days and 10 microg ethinyl estradiol for 5 days (Mircette/ethinyl estradiol; N = 23).


RESULTS
During cycles 2 and 3, the Mircette/placebo group had a higher incidence of persistent ovarian follicles (eight subjects versus three subjects) and on average a greater maximum follicle diameter than the Mircette/ethinyl estradiol group. One Mircette/placebo subject probably ovulated in cycle 2, and another had a luteinized unruptured follicle; no such activity was seen in the in the Mircette/ethinyl estradiol group. The study medication was well tolerated, and there were no apparent between-group differences in vaginal bleeding patterns.


CONCLUSIONS
The Mircette regimen, which includes low ethinyl estradiol doses during the hormone-free interval, more effectively suppresses ovarian follicular activity with a low monthly estrogen dose.
School of Medicine, University of Hull, Stepping Hill Hospital, Kingston upon Hull, United Kingdom.
S R
SR
Killick
C
C
Fitzgerald
A
A
Davis
D000293:Adolescent; D000328:Adult; D003277:Contraceptives, Oral, Combined / Q000627:therapeutic use*; D017135:Desogestrel / Q000008:administration & dosage / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004338:Drug Combinations; D004958:Estradiol / Q000097:blood; D004997:Ethinyl Estradiol / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000187:drug effects; D006080:Ovarian Follicle / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000254:growth & development; D011374:Progesterone / Q000097:blood; D012016:Reference Values; D014463:Ultrasonography
D003277:Contraceptives, Oral, Combined; D004338:Drug Combinations; D004997:Ethinyl Estradiol; D011374:Progesterone; D004958:Estradiol; C034653:Oviol; D017135:Desogestrel