Leptin, VEGF, IGF-1, and IGFBP-3 concentrations in serum and follicular fluid of women undergoing in vitro fertilization

We studied the influence of recombinant follicle-stimulating hormone (rFSH) stimulation on the concentration of leptin, vascular endothelial growth factor (VEGF), insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) in serum and follicular fluid (FF) in women undergoing assisted reproduction. To test the hypothesis that these hormones could predict successful implantation and that the levels correlate with pregnancy rate. Sequential serum samples were drawn at the beginning of stimulation and on the day of embryo transfer (ET) from 84 women undergoing IVF. The follicular fluid (FF) obtained during oocyte retrieval was collected and the concentration of leptin, VEGF, IGF-1 and IGFBP-3 were measured in all samples. The hormones were measured by commercially available IRMA, RIA or EIA. Patients' characteristics and results of the assisted reproductive cycles were registered. Serum concentrations of VEGF, IGF-1 and IGFBP-3 significantly decreased during rFSH treatment. In contrast, serum leptin significantly increased after rFSH treatment. A strong correlation was found between the FF – levels of IGF-1, IGFBP-3, leptin and respective serum levels. With regard to IVF outcome, higher serum concentrations of IGF-1, IGFBP-3 and VEGF on the day of oocyte retrieval were observed in conception cycles vs. non-conception cycles. No such difference, however, was apparent at the beginning of the stimulation cycle. There was no association between FF levels of any of these hormones and IVF outcome. Our results demonstrate that VEGF, IGF-1, IGFBP-3 and leptin levels are affected by rFSH during controlled ovarian hyperstimulation and that there is a direct association between serum and FF levels, albeit without clinical implications