Peripheral levels of vascular endothelial growth factor (VEGF) are higher in gonadotropin stimulated as compared to natural ovarian cycles

The purpose of the present study was to investigate the stability of vascul ar endothelial growth factor (VEGF) in plasma samples and the influence of ovarian hyperstimulation on systemic levels of VEGF. Stability assays for V EGF in plasma samples revealed significant increases following even short i ncubations of samples at room temperature (less than or equal to2 h, p <0.0 01). To investigate a possible impact of controlled ovarian hyperstimulatio n (COH) on peripheral VEGF levels, serial blood collection over one menstru al cycle was performed in unstimulated as well as in gonadotropin-stimulate d cycles for in vitro fertilisation / embryo transfer (IVF/ ET) (10 women e ach). Peripheral levels for VEGF were significantly higher in gonadotropin stimulated cycles as compared to non-stimulated cycles (p<0.001). There was no significant difference between follicular phase and luteal phase levels in either Group. VEGF levels tended to correlate with the number of follic les detected by vaginal sonography prior to oocyte aspiration (p = 0.051). In conclusion, VEGF levels are elevated in gonadotropin-stimulated-IVF/ET c ycles as compared to natural cycles.