Cerebrovascular Function in Pregnancy and Eclampsia

H ypertension is one of the most common medical com- plications of pregnancy that affects both fetal and maternal health and is often life threatening. 6] The major cerebrovascular changes in eclampsia have been shown to be similar to those described for hypertensive encephalopathy, including loss of cerebral blood flow (CBF) autoregulation, hyperperfusion, and edema. 8 -12 3] It is well known that pregnancy is associated with significant cardiovascular adaptation of both local and systemic circulations. 2,19 -22 Although the vascular changes that occur during pregnancy have been the subject of intense study in many organs, the effect of pregnancy and hypertension during pregnancy on the cerebral circulation is just coming to be understood. This review focuses on structural and functional changes in the cerebral circulation during normal pregnancy and the postpartum state that may contribute to the development of eclampsia, including changes in CBF autoregulation and cerebrovascular resistance (CVR) that enhance BBB permeability and hydrostatic brain edema. In addition, how hypertension during pregnancy, being somewhere between acute and chronic hypertension, affects the cerebral circulation is discussed.