Preeclampsia: Pathophysiology
Jorge Muniz
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General Features
- Preeclampsia is classically defined as the new onset of hypertension and proteinuria after 20 weeks of gestation
- New onset hypertension with significant end-organ dysfunction (with or without proteinuria) after 20 weeks of gestation also satisfies the diagnosis of preeclampsia
- Severe headache, epigastric or right upper quadrant pain, visual disturbances, thrombocytopenia, impaired liver function, renal insufficiency, pulmonary edema
- HELLP syndrome: Hemolysis, Elevated Liver enzymes, Low Platelets
- Edema may or may not be present
- New onset hypertension with significant end-organ dysfunction (with or without proteinuria) after 20 weeks of gestation also satisfies the diagnosis of preeclampsia
- Eclampsia = preeclampsia + seizures
- Risk factors include nulliparity, past history of preeclampsia, preexisting hypertension or renal disease, autoimmune disease, very young or advanced maternal age, diabetes, and obesity
- Curative treatment is delivery
Pathophysiology
- Genetic and immunological factors
- Defective spiral artery remodeling during pregnancy
- During a normal pregnancy trophoblast cells invade the myometrial segment of the spiral arteries to cause transformation and dilation of the arteries
- In preeclampsia there is insufficient trophoblast cell invasion, which causes the spiral arteries to remain narrow and leads to placental hypoperfusion
- Diseased placenta releases proinflammatory proteins
- Hypertension
- Vasoconstriction
- Endothelial cell dysfunction
- Formation of thrombi
- End-organ damage