Abnormal endothelium-dependent microvascular dilator reactivity in pregnancies complicated by normotensive intrauterine growth restriction.

Abstract

Normotensive intrauterine growth restriction and preeclampsia share a similar placenta pathophysiology, whereas maternal clinical manifestations differ. Clinical symptoms of preeclampsia are partly attributed to vascular endothelial dysfunction, but it is unclear whether this phenomenon plays a role in intrauterine growth restriction. Therefore, we investigated microvascular endothelial function in women with intrauterine growth restriction. Laser Doppler fluxmetry was used combined with iontophoresis of acetylcholine and sodium nitroprusside, namely, endothelium-dependent and endothelium-independent vasodilators. We studied 12 women with intrauterine growth restriction and 16 controls in the third trimester of pregnancy. All women had prepregnancy body mass indexes < 26. Acetylcholine-mediated vasodilatation was significantly increased in women with intrauterine growth restriction compared with controls (743% +/- 120% vs 390% +/- 67%, P = .01); sodium nitroprusside-mediated vasodilatation was not different (360% +/- 55% vs 363% +/- 65%, P > .99). Nonobese women with normotensive intrauterine growth restriction show abnormal endothelium-dependent microvascular vasodilatation, suggesting endothelial dysfunction as in preeclampsia. Obviously, for the clinical manifestation of preeclampsia additional factors are required, and a role of metabolic syndrome and obesity has been suggested.