Plasma levels of free vascular endothelial growth factor165 (VEGF165) are not elevated during gonadotropin stimulation in in vitro fertilization (IVF) patients developing ovarian hyperstimulation syndrome (OHSS):: results of a prospective cohort study with matched controls

Objective: To evaluate whether differences in plasma vascular endothelial growth factor(165) (VEGF(165)) concentrations exist during gonadotropin stimulation in IVF patients developing severe ovarian hyperstimulation syndrome (OHSS) compared to matched controls. Study design: Prospective cohort study with comparison of 15 OHSS cases with 30 matched (agc, follicle numbers, pregnancy) controls. Unpaired students t-test was used to evaluate differences between the OHSS and control group and correlations were calculated with Pearson's test. Result(s): Plasma levels of VEGF(165), at four time-points from start of gonadotropin stimulation to embryo transfer (ET), were compared and related to steroid levels and ultrasound data. There were no differences between OHSS and control patients in plasma VEGF(165) levels at any of the four time points, which were compared. The mean levels were between 53-83 pg ml(-1) and 64-83 pg ml(-1) in the OHSS and control group, respectively. Positive correlations existed between total number of follicles, number of large (> 15 mm) follicles and VEGF(165) at day of oocyte aspiration and between VEGF(165),S and progesterone at ET in the control gn,up. hut not in the OHSS group. Conclusion(s): Patients developing OHSS do not have raised plasma VEGF(165) levels during gonadotropin stimulation. The lack of positive correlation between VEGF165 levels and follicle numbers/progesterone in the OHSS group, suggests a disruption in OHSS of the normal controlled follicular VEGF expression. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.