[Arterial hypertension in pregnancy: current concepts].

Although the term hypertension in pregnancy is a simple and uncontroversial one, it unfortunately encompasses some ill defined clinical conditions as well as pre-eclampsia. The prime cause of pre-eclampsia is utero-placental ischaemia. Such utero-placental ischaemia is responsible for the hypothetical secretion of a vasopressor agent and for intravascular coagulation. An immunological cause should also be suspected: a study of the immune profile of the kidney has shown that the glomerular capillaries contain immunoglobulins G and M as well as the C3 fraction of complement. Renal biopsies carried out three months after delivery have shown deposits of C3 in the arteriolar walls. During normal pregnancy, there exists a state of stable equilibrium of hormonal, haemodynamic, haematological and immunological factors. It seems that all components of this equilibrium are disturbed in cases of hypertension in pregnancy.