Preeclampsia and hypertensive disorders of pregnancy.

Hypertensive conditions encountered during pregnancy are classified as preeclampsia, transient hypertension and chronic hypertension. The pathophysiology, consequences and management of these disorders differ, but their clinical presentations overlap substantially. Preeclampsia is a syndrome of the second half of pregnancy, characterized by hypertension, edema and proteinuria, but all three findings are not required to make the diagnosis. Preeclampsia can progress unpredictably to a variety of crises, including eclamptic seizures, and contributes significantly to maternal and perinatal mortality. Management consists of prompt delivery for a mature fetus. Management of preeclampsia at earlier stages of gestation requires balancing the risks of immediate delivery of an immature fetus against the risks to both mother and child of a complication of preeclampsia. Transient hypertension is a clinically benign condition characterized by isolated high blood pressure in late pregnancy; its significance lies in the difficulty of distinguishing it from early preeclampsia. Chronic hypertension is a risk factor for intrauterine growth restriction and intrauterine fetal demise, as well as for preeclampsia. The management strategy consists of control of maternal blood pressure, ongoing antepartum assessment of fetal well-being and surveillance for superimposed preeclampsia.