Maternal Vascular Physiology in Preeclampsia.

Preeclampsia is a systemic syndrome that occurs during pregnancy and postpartum and affects 3% to 8% of pregnancies. It is one of the leading causes of maternal and neonatal mortality and morbidity worldwide. The American College of Obstetricians and Gynecologists and the International Society for the Study of Hypertension in Pregnancy have set the following criteria for the clinical diagnosis of preeclampsia: de novo maternal hypertension (>140/90 mm Hg) with proteinuria (0.3 g per 24 hours) after 20 weeks of gestation or hypertension combined with hematologic complications, impaired renal and liver function, neurological symptoms, or uteroplacental dysfunction. This broad definition reflects the heterogeneity in clinical presentation of preeclampsia, which suggests heterogeneity in the pathogenesis of this syndrome. Maternal vascular dysfunction and abnormal hemodynamics are common features of preeclampsia and may be evident in both reproductive and nonreproductive vascular beds. Components of aberrant vascular physiology in preeclampsia include impaired vascular endothelial function, incomplete uterine artery remodeling, augmented vasoconstriction, vascular oxidative stress, and inflammation Studies using flow-mediated dilation have shown that women who had preeclampsia had lower flow-mediated dilation before clinical diagnosis of preeclampsia, at the time of preeclampsia, and for 3 years postpartum, suggesting that vascular dysfunction may play a role in the pathogenesis of preeclampsia and may be a link between preeclampsia and high risk for cardiovascular disease later in life. The main objective of this brief review is to discuss the molecular mechanisms underlying aberrant maternal vascular physiology in reproductive and nonreproductive vascular beds in preeclampsia. Evidence from studies in experimental animals and in humans will be discussed. Currently, there is lack of evidence that species other than humans spontaneously develop preeclampsia. Therefore, animal models resembling preeclampsia-like features that are induced by experimentation will be referred as models of experimental preeclampsia.