Pregnancy is a cardiovascular and metabolic challenge to the human female body. This review summarizes current knowledge on the regulation of blood pressure and plasma volume in normal and hypertensive pregnant women. During pregnancy, systemic vascular resistance and blood pressure decrease, whereas cardiac output and blood volume increase to safeguard an adequate circulation in the utero-placental arterial bed. Hypertension affects 10% of all pregnancies and is accompanied by an increase in foetal and maternal morbidity and mortality. Hypertension in pregnancy includes a wide spectrum of conditions, including pre-eclampsia and eclampsia, pre-eclampsia superimposed on chronic hypertension, chronic hypertension, and gestational hypertension...