Hypothalamic-pituitary-ovarian response to clomiphene citrate in women with polycystic ovary syndrome

• Published in: Fertility and sterility Vol. 59; no. 3; p. 532
• Main Authors: Kettel, L M, Roseff, S J, Berga, S L, Mortola, J F, Yen, S S
• Format: Journal Article
• Language: English
• Published: United States 01-03-1993
• Subjects: Adolescent; Adult; Clomiphene - pharmacology; Clomiphene - therapeutic use; Estradiol - blood; Estrone - analogs & derivatives; Estrone - blood; Female; Follicle Stimulating Hormone - blood; Humans; Hypothalamo-Hypophyseal System - drug effects; Luteinizing Hormone - blood; Ovary - drug effects; Polycystic Ovary Syndrome - drug therapy; Polycystic Ovary Syndrome - physiopathology; Pregnanediol - analogs & derivatives; Pregnanediol - blood; Prospective Studies
• ISSN: 0015-0282
• DOI: 10.1016/S0015-0282(16)55795-1

To examine the hypothalamic-pituitary sites of clomiphene citrate (CC) action in women with polycystic ovarian syndrome (PCOS).
Prospective controlled trial.
Seventeen women with PCOS and 9 normal-cycling women.
Subjects with PCOS received CC, 150 mg/d for 5 days.
Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels and LH pulse characteristics and their response to gonadotropin-releasing hormone (GnRH, 10 micrograms) were examined before and after 3 days of CC in PCOS subjects during a 12-hour frequent sampling study (n = 8). Daily urinary estrone glucuronide and pregnanediol glucuronide levels after CC were compared with concentrations in normal-cycling women through one menstrual cycle. In another nine PCOS subjects, pituitary and ovarian hormonal cyclicity was monitored by daily blood sampling.
Thirteen of 17 treated cycles were ovulatory with normal luteal phases. In the ovulatory cycles, serum LH, FSH, estradiol (E2), and estrone levels increased after CC. Luteinizing hormone pulse frequency was unchanged, but LH pulse amplitude increased significantly after CC. Both LH and FSH response to exogenous GnRH was significantly attenuated after CC treatment. In anovulatory cycles, serum LH, FSH, and E2 increased initially and then returned to baseline and remained unchanged for the ensuring 40 days.
Clomiphene citrate-induced ovulation in women with PCOS is accompanied by increased secretion of LH and FSH with enhanced estrogen secretion. The increased LH pulse amplitude after CC, together with decreased pituitary sensitivity to GnRH, suggests a hypothalamic effect.