Physiological balance between fVEGF and sVEGFR1 is maintained within ovarian follicles in normoresponder women irrespective of GnRH-agonist and GnRH-antagonist protocols

Abstract The hypothesis that there exists a differential association between total free VEGF (fVEGF) and soluble VEGF-receptor1 (sVEGFR1) in follicular fluid obtained from GnRH-agonist (GnRH-a) versus GnRH-antagonist (GnRH-ant) protocols was examined. It was observed that: (i) concentration of total fVEGF in follicular fluid retrieved from GnRH-ant group was higher than that in GnRH-a group, (ii) it was three-times higher than that of VEGF-A alone as reported in the previous study, and (iii) follicular concentration of sVEGFR1 showed no significant difference between two groups. Finally, our hypothesis that ratios of follicular sVEGFR to fVEGF might show differential profiles between two protocols was not found tenable. We conclude that the physiological balance between sVEGFR1 and total fVEGF is maintained within a ratio of 2–3 in ovarian follicles in normoresponder women irrespective of GnRH-a and GnRH-ant protocols.