title: Single monthly administration of the anti-progestagen Org 31710 in users of the 75 microg desogestrel progestagen-only pill: effects on pituitary-ovarian activity.
abstract: Endocrine and ultrasound effects were studied of an intermittent (every 28 days) oral administration of 150 mg of the anti-progestagen Org 31710 during the continued daily use of 75 microg desogestrel (DSG) for progestagen-only contraception. A randomized, double-blind, placebo-controlled two-centre study was conducted in 50 healthy volunteers. Serum luteinizing hormone (LH), follicle stimulating hormone (FSH), oestradiol and progesterone concentrations, and follicle number and size were studied, as well as endometrial thickness, which was assessed by transvaginal sonography at least twice weekly during a single medication cycle (cycle 3-5). Forty-eight women were evaluated (Org 31710, n = 25; placebo, n = 23). Seven ovulations were observed in the treated group versus none in the placebo group. LH concentrations were higher on days 9 and 11 and oestradiol concentrations lower on day 3 in the treated group, irrespective of whether ovulation occurred. No parameter could predict ovulation. Endometrial thickness was greater on cycle days 7-13 and 19 in the treated group. However, within the Org 31710 group, no significant differences were found in volunteers who did or did not ovulate. Observed differences may be attributed to a competitive effect of Org 31710 with progestagen-induced suppression of the pituitary-ovarian axis, altered oestradiol feedback mechanisms, and/or altered receptor availability.
authors.affiliation: Division of Reproductive Medicine, Department of Obstetrics and Gynaecology, Erasmus University Medical Centre Rotterdam, 3015 GD Rotterdam, The Netherlands.
authors.forename: A M
authors.initials: AM
authors.lastname: van Heusden
authors.forename: S R
authors.initials: SR
authors.lastname: Killick
authors.forename: H J
authors.initials: HJ
authors.lastname: Coelingh Bennink
authors.forename: B C
authors.initials: BC
authors.lastname: Fauser
mesh_terms: D000293:Adolescent; D000328:Adult; D003280:Contraceptives, Oral, Synthetic / Q000008:administration & dosage*; D017135:Desogestrel / Q000008:administration & dosage*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004717:Endometrium / Q000033:anatomy & histology / Q000187:drug effects; D004958:Estradiol / Q000097:blood; D004963:Estrenes / Q000008:administration & dosage*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D005663:Furans / Q000008:administration & dosage*; D006727:Hormone Antagonists / Q000008:administration & dosage*; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D010053:Ovary / Q000187:drug effects* / Q000502:physiology; D010060:Ovulation / Q000187:drug effects; D010902:Pituitary Gland / Q000187:drug effects* / Q000502:physiology; D010919:Placebos; D011374:Progesterone / Q000097:blood
chemical_list: D003280:Contraceptives, Oral, Synthetic; D004963:Estrenes; D005663:Furans; D006727:Hormone Antagonists; D010919:Placebos; C076196:Org 31710; D011374:Progesterone; D004958:Estradiol; D017135:Desogestrel; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone