Maternal plasma vascular endothelial growth factor concentrations in normal and hypertensive pregnancies and their relationship to peripheral vascular resistance

OBJECTIVE: The aim of this study was to measure maternal plasma vascular en dothelial growth factor concentrations during normal and hypertensive pregn ancies and examine their relationship with maternal total peripheral resist ance values. STUDY DESIGN: Plasma concentrations of total immunoreactive Vascular endoth elial growth factor and total peripheral resistances were measured serially throughout pregnancy in 20 women with preeclampsia, 24 women with gestatio nal hypertension, and 26 normotensive control women. One-way analysis of va riance and a regression model were used to analyze the vascular endothelial growth factor levers in the groups and the relationship between vascular e ndothelial growth factor concentration and total peripheral resistance. RESULTS: At 10 to 14 weeks' gestation plasma vascular endothelial growth fa ctor concentrations in all subjects were 4 to 5 times greater than the leve ls measured post partum (P < .0001). Mean Vascular endothelial growth facto r concentrations were similar in the control and gestational hypertension g roups; in both groups levels remained stable until 34 to 36 weeks' gestatio n, when levels increased a further 1.3-fold (P < .01). in comparison, vascu lar endothelial growth factor concentrations in subjects in the preeclampsi a group were greater at 28 to 32 weeks' gestation (P = .002) and at 34 to 3 6 weeks' gestation (P < .001). Vascular endothelial growth factor concentra tions were also increased during the 4 weeks that preceded the diagnosis of preeclampsia (P < .05). Vascular endothelial growth factor concentrations were associated with the elevated total peripheral resistance observed duri ng the clinical disorder in the preeclampsia group but not in the other gro ups. CONCLUSION: Maternal plasma vascular endothelial growth factor concentratio ns increased before the clinical onset of preeclampsia and were further ele vated during the vasoconstricted slate observed in this disorder. We specul ate that the hyperdynamic circulation that characterizes the latent phase o f preeclampsia causes vascular shear stress, which in turn increases the le vels of circulating vascular endothelial growth factor. Because vascular en dothelial growth factor normally acts as a vasodilator, its increase may re present an unsuccessful vascular rescue response.