Classification and pathogenesis of preeclampsia: contemporary concepts

Preeclampsia is a systemic hypertensive disorder that develops during pregnancy and is typical only for humans. Persistent high blood pressure and associated organ damage have a negative impact on the mother and child organisms not only during pregnancy, but also exposes them to the risk of cardiovascular and cerebrovascular complications later in life. Despite many years of research, the etiology and pathogenesis of preeclampsia have not been sufficiently studied, while currently available therapeutic methods remain ineffective. This review analyzes the contemporary concepts on the types and stages of preeclampsia, as well as on pathomorphological changes in the placenta and blood vessels tissues. Depending on gestational age, pathophysiology and clinical consequences for the mother, two types of PE are currently distinguished — preeclampsia with early onset (before 34 weeks of pregnancy) and preeclampsia with late onset (at/after 34 weeks or after delivery). Preeclampsia with early manifestation is recognized as a consequence of defective placentation, while the pathology of maternal cardiovascular system is the main cause of the late disease onset. In both cases an impaired placental perfusion leads to numerous morphological anomalies and deposition of fibrotic tissue in the placenta and vessels.