Polycystic ovarian syndrome is a common cause of infertility in females. One approach to treatment is increasing ovarian exposure to follicle stimulating hormone (FSH).
Patients with polycystic ovarian syndrome (PCOS) suffer from hyperandrogenism and hyperestrogenism. Hyperestrogenism obstructs the menstrual cycle by inhibiting production of the gonadotropins, follicle stimulating hormone (FSH) and luteinizing hormone (LH), via negative feedback. The absence of gonadotropins leads to anovulation and infertility. Clomiphene may be used to treat infertility in PCOS, and is a partial agonist of estrogen receptors in the hypothalamus that prevents feedback inhibition of LH and FSH. The resulting increase in these circulating gonadotropins stimulates ovulation.
Radosh reviews the diagnosis and treatment options for PCOS. They report that metformin and clomiphene, alone or in combination, are first-line agents for ovulation induction.
Nader reviews the pathogenesis of infertility and treatment options in PCOS. They report that ovulation induction in PCOS requires increasing ovarian exposure to follicle stimulating hormone (FSH) and/or correcting hormonal derangements.
Illustration A is an ultrasound showing polycystic ovarian syndrome.
Answer 1: Increased estrogen levels are a frequent cause of anovulation in PCOS. Reducing estrogen levels is a goal of therapy in both PCOS and PCOS-induced infertility.
Answer 2: Leptin is an adipose-derived hormone important in nutrient consumption and energy expenditure. It is not associated with infertility in PCOS.
Answer 3: Prolactin is a peptide hormone with several actions, including the regulation of postpartum lactation. Prolactin inhibits ovulation.
Answer 5: The fetal placenta produces human chorionic gonadotropin following fertilization. It promotes the maintenance of the corpus luteum during the beginning of pregnancy.
Radosh L. Drug treatments for polycystic ovary syndrome. Am Fam Physician. 2009 Apr 15;79(8):671-6. Review
PMID:19405411 (Link to Abstract)
Nader S. Infertility and pregnancy in women with polycystic ovary syndrome. Minerva Endocrinol. 2010 Dec;35(4):211-25. Review
PMID:21178917 (Link to Abstract)
USMLE World Step 1 Qbank Question #2095. Copyright © USMLEWorld, LLC 2012