Soluble VEGFR-1 in pathophysiology of pregnancies complicated by hypertensive disorders: the Indian scenario

An imbalance between angiogenic and anti-angiogenic factors has been hypothesized to have a major role in hypertensive disorders during pregnancy, which account for significant morbidity and mortality for the mother and neonate in India. There is a paucity of information on soluble vascular endothelial growth factor receptor-1 (sVEGFR-1, anti-angiogenic factor) concentrations in different subgroups of pregnancy-induced hypertensive (PIH) disorders particularly in gestational hypertension (GH) and eclampsia during pregnancy. This cross-sectional study was conducted in order to test the above hypothesis and to get more insight into the role of sVEGFR-1 in these disorders. The concentrations of sVEGFR-1 in serum were measured from women with 22-39 weeks of gestation in the control (n=180) and gestationally matched hypertensive (n=360) pregnant mothers by ELISA. These sVEGFR-1 concentrations were found to be significantly elevated in the study groups as the severity of disease increases from GH to eclampsia (24 076 pg ml(-1); 42000 pg ml(-1), P=0.0001) as compared with controls (3360 pg ml(-1)). According to Receiver operating characteristic curve analysis, at ≤ 34 weeks, the concentration cutoff, sensitivity, specificity for sVEGFR-1 in differentiating GH, pre-eclampsia and eclampsia were ≥ 7619.2 pg ml(-1), 75%, 75%; ≥ 16726.6 pg ml(-1), 89.1%, 89.1%; ≥ 26222.8 pg ml(-1), 91.6%, 91.6%, respectively. The gradual upregulation of sVEGFR-1 concentrations in these groups may be due to its intimate involvement in the etiopathogenesis of severity of various hypertensive disorders by antagonizing effects of VEGF during the placental development. These observations indicate the clinical utility of sVEGFR-1 in differentiating PIH disorders and also will be helpful for the evaluation of increased monitoring system for successful pregnancy.