[Hypertension and pregnancy: physiopathology, treatment, prevention].

Pathophysiologic understanding of the hypertensive diseases of pregnancy has largely progressed in the past 10 years. The key phenomenon is an early defect of placentation, occurring at the end of first trimester. It is associated with a more global endothelial disorder. This results in early activation of coagulation, and an imbalance between prostacyclin and thromboxanes. Hypertension and proteinuria only occur after several weeks or months of placental dysfunction. This explains why antihypertensive treatments are ineffective in improving the prognosis of such pregnancies. On the contrary, early preventive treatments, such as antiplatelet therapy, seem very promising for those patients.