Introductory Chapter: The Multiple Etiologies of Preeclampsia

Abstract

Preeclampsssia or “gestosis” or “toxemia of pregnancy” is any condition predisposing to eclampsia or convulsions during pregnancy. The word eclampsia is derived from a Greek word eklampsis meaning “lightening” or convulsions. Preeclampsia is speculated to be a heterogeneous group of disorders caused by multiple etiologies. Understanding the pathophysiology of this syndrome is important as different etiologies have different pathological mechanisms and different predictive markers. Though the defect could have arisen in the renin-angiotensin system, cardiovascular system, liver enzyme deficiency, coagulation cascade, oxidative stress, or placental bed, the clinical picture is usually oversimplified as the maternal syndrome of hypertension, edema, and proteinuria. The third world countries will benefit from the provision of adequate antenatal care after these high-risk women are identified. In the developed world, however, the emphasis is on early detection and prevention of preeclampsia. During pregnancy, the physiology of cardiovascular system, renin-angiotensin system, pancreas changes, different organ reserves are put to test. Understanding preeclampsia requires the understanding of physiology of pregnancy. The blood flow in multiple organs is increased (Figure 1). Numerous studies at the embryo-endometrial interphase have also suggested the association of impaired spiral artery remodeling in preeclampsia, but how exactly is the impaired remodeling mediated and what is the pathogenesis of maternal syndrome are still to be elucidated. Some clinical cases of maternal syndrome of preeclampsia also have normal placental histology, so all cases cannot be attributed to a primary placental defect.