Vascular endothelial growth factor and basic fibroblast growth factor in polycystic ovary syndrome during controlled ovarian hyperstimulation

Background. Polycystic ovary syndrome (PCOS) is a common endocrine disorder that causes anovulation and consequent subfertility. It is well established that increased ovarian mass, supported by new blood vessel proliferation in stroma and theca, is a key feature of PCOS. Recent studies suggest a role for angiogenetic factors in this phenomenon. Aim. To evaluate of levels of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in serum and follicular fluid of PCOS patients during a controlled ovarian hyperstimulation. Methods. In 52 patients undergoing in vitro fertilization treatments, 26 PCOS patients and 26 controls, serum VEGF and bFGF levels were assessed before starting administration of follicle-stimulating hormone (FSH) (day 0), on the day of administration of human chorionic gonadotropin (hCG) and on the day of oocyte retrieval. Follicular fluid levels of the two growth factors were detected on the day of oocyte retrieval. Results. PCOS patients showed higher serum VEGF levels than controls before starting FSH administration, on the day of hCG administration and on the day of oocyte retrieval. Serum VEGF levels showed a rise after hCG administration only in the PCOS patients. In addition, serum bFGF levels were higher in PCOS patients than in controls on the day of hCG administration and the day of oocyte retrieval. Furthermore, on the day of hCG administration, serum bFGF levels were directly correlated to the amount of FSH previously administered (p < 0.0001). In follicular fluid, higher VEGF and bFGF levels were found in PCOS patients than in controls. Furthermore, follicular-fluid bFGF concentrations were inversely correlated with the percentage of mature oocytes collected (p < 0.05). Conclusions. The present study revealed elevated levels of VEGF and bFGF in serum and follicular fluid in PCOS patients compared with controls. bFGF seems to be an FSH-dependent growth factor and its levels in follicular fluid are inversely correlated with the percentage of mature oocytes collected.