Therapeutic strategies for ovulation induction in infertile women with polycystic ovary syndrome.
Polycystic ovary syndrome (PCOS) is a heterogeneous disorder characterized by hirsutism, obesity, hyperandrogenism and insulin resistance. The syndrome is often accompanied by infertility because of anovulation. Many approaches have been proposed to solve this problem, with the most commonly used therapies being ovarian drilling and pharmacological ovulation induction. Ovarian drilling is a procedure in which a laser fiber or electro-surgical needle punctures the ovary four to ten times. Side-effects are rare and often related to surgery itself. Pharmacological strategies include administration of metformin and insulin-sensitizing agents, clomiphene citrate (CC), gonadotropins and aromatase inhibitors. Metformin appears valuable in increasing ovulation rate, menstrual cyclicity and pregnancy rate. CC is an oral estrogen antagonist that raises circulating concentrations of follicle-stimulating hormone (FSH) and induces follicular growth in most women with PCOS and anovulation. Failure to respond is associated with high body mass index and high androgen levels. Aromatase inhibitors mimic the central reduction of negative feedback through which CC works. Ovulation induction with recombinant FSH has proved successful, but treatment requires skill and experience to avoid multiple pregnancies and ovarian hyperstimulation syndrome. The hypothetical deleterious effects of the high luteinizing hormone concentrations observed in PCOS patients seem to be related to the concomitant hyperinsulinemia (and/or insulin resistance). A thorough understanding of the syndrome and a careful assessment of each patient are the mainstays for choosing an appropriate treatment regimen.