Poor responder-high responder: the importance of soluble vascular endothelial growth factor receptor 1 in ovarian stimulation protocols

This study was designed to detect vascular endothelial growth factor (VEGF) and its soluble receptor (sVEGFR-1) in follicular fluid specimens and to e valuate the importance of sVEGFR-1 with respect to ovarian response to gona dotrophin stimulation. A total of 69 patients was treated for IVF with reco mbinant human follicle stimulating hormone (FSH), Concentrations of VEGF an d sVEGFR-1 were quantified in follicular fluids from oocyte retrievals, Pat ients were designated to three groups with respect to the number of harvest ed oocytes: group A, 1-5 oocytes; group B, 6-10 oocytes; group C, >10 oocyt es, In group A, 1133 +/- 870 pg VEGF/ml follicular fluid per oocyte were qu antified, in group B 426 +/- 262 pg VEGF/ml per oocyte, and in group C 274 +/- 179 pg VEGF/ml per oocyte, Soluble VEGFR-1 concentrations resulted in 1 200 +/- 523 pg/ml follicular fluid per oocyte in group A, 255 +/- 193 pg/ml per oocyte in group B, and 79 +/- 69 pg/ml per oocyte in group C, No free sVEGFR-1 could be detected in any follicular fluid. An index to estimate th e biological activity of VEGF by dividing VEGF/sVEGFR-1 revealed an increas ing availability of VEGF with higher ovarian response to gonadotrophin ther apy. In group A this index was 1.03, in group B 1.71, and in group C 3.21, A delicate balance between VEGF and sVEGFR-1 is necessary to allow an adequ ate ovarian reaction to gonadotrophin therapy. Excess of bio-active VEGF in creases the risk for ovarian hyperstimulation syndrome. Excess of sVEGFR-1 results in poor response and goes in parallel with reduced chances for conc eption.