Effect of GnRH agonist and hCG treatment on VEGF, angiopoietin-2, and VE-cadherin: trying to explain the link to ovarian hyperstimulation syndrome.

This study evaluated the differentially modulated expression of vascular mediators in oocyte donors after hCG vs. GnRHa triggering, trying to understand ovarian hyperstimulation syndrome pathophysiology. Donors who received GnRH agonist triggering showed a statistically significant decrease in vascular endothelial growth factor in follicular fluid and in mRNA expression in granulosa cells, with no differences in angiopoietin 2 and vascular endothelial cadherin levels in serum or follicular fluid. This differential regulation of vascular endothelial growth factor by hCG might explain the higher likelihood of ovarian hyperstimulation syndrome following hCG administration compared with GnRH agonists.