[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Female genital tract](https://durgical.com/en/general-pathology/areas/female-genital/) › Preeclampsia and eclampsia # Preeclampsia and eclampsia - Mechanism A poorly built placenta releases factors that damage the mother's blood vessels; blood pressure rises and organs fail until the placenta is delivered. Updated Nov 12, 2026 ## Key points - Normal pregnancy: invasive trophoblast replaces the muscle of the spiral arteries, turning them into wide, low-resistance channels. - Preeclampsia: shallow invasion leaves narrow muscular arteries; the placenta is underperfused. - The ischaemic placenta releases soluble Flt-1 (traps VEGF and PlGF) and soluble endoglin (blocks TGF-beta): endothelial dysfunction, less nitric oxide and prostacyclin, more endothelin and thromboxane. - Clinical tests: a high sFlt-1 to PlGF ratio supports the diagnosis and predicts the course. - Kidney: glomerular endotheliosis (swollen endothelium closing capillary lumens) with proteinuria. - Liver: periportal fibrin, haemorrhage and necrosis, subcapsular haematoma; brain: oedema and haemorrhage (posterior reversible encephalopathy), seizures. ## What it is Preeclampsia is a pregnancy syndrome of new hypertension after 20 weeks with proteinuria or other organ dysfunction; eclampsia adds seizures, and HELLP syndrome adds haemolysis, raised liver enzymes and low platelets. Its root is an abnormal placenta: the trophoblast fails to remodel the maternal spiral arteries, the placenta becomes ischaemic and releases antiangiogenic proteins, soluble Flt-1 and soluble endoglin, that block VEGF, PlGF and TGF-beta signalling. The result is widespread endothelial dysfunction, vasoconstriction, leaky vessels and clotting. Delivery of the placenta is the cure. ## Structure - Placenta: small for gestational age; infarcts, retroplacental haematoma, distal villous hypoplasia, accelerated maturation and increased syncytial knots. - Decidual arteries: fibrinoid necrosis with lipid-laden macrophages (acute atherosis) and no physiologic remodelling. - Kidney: enlarged bloodless glomeruli with swollen endothelial cells and subendothelial fibrin. - Liver: fibrin thrombi in periportal sinusoids with haemorrhagic necrosis. ## Step by step - In early pregnancy, extravillous trophoblast fails to invade and remodel the spiral arteries. - The arteries stay narrow and muscular; the placenta suffers ischaemia and oxidative stress. - The stressed placenta releases soluble Flt-1 and soluble endoglin into the maternal blood. - These factors neutralise VEGF, PlGF and TGF-beta, which keep the endothelium healthy. - Systemic endothelial dysfunction causes vasoconstriction (hypertension), leaky capillaries (proteinuria, oedema) and platelet and coagulation activation. - Organ damage follows: kidney, liver, brain, placenta; HELLP and DIC in severe cases. ## Clinical notes - Risk factors: first pregnancy, previous preeclampsia, chronic hypertension, diabetes, kidney disease, obesity, antiphospholipid syndrome, multiple or molar pregnancy, older maternal age. - Warning signs: severe headache, visual disturbance, epigastric or right upper quadrant pain, rising blood pressure; seizures mean eclampsia. - Hypertensive disorders of pregnancy are a leading cause of maternal death in Colombia and Latin America; women with preeclampsia carry a higher lifelong cardiovascular risk. ## Memory aid A shallow root makes a thirsty placenta, and the thirsty placenta poisons the mother's endothelium until it is delivered. ## Test yourself Think of the answer, then tap the question to see it. ## What placental abnormality underlies preeclampsia? Failure of trophoblast to remodel the spiral arteries, which stay narrow and muscular and leave the placenta ischaemic. ## How do soluble Flt-1 and soluble endoglin cause the maternal disease? They trap VEGF and PlGF and block TGF-beta signalling, which the endothelium needs, producing systemic endothelial dysfunction. ## What is the typical kidney lesion of preeclampsia? Glomerular endotheliosis: swollen endothelial cells occluding the capillary lumens, with proteinuria. ## What is HELLP syndrome? A severe form with haemolysis, elevated liver enzymes and low platelets, from microangiopathy and periportal liver injury. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/general-pathology/preeclampsia-and-eclampsia/) [More Pathology questions →](https://durgical.com/en/practice/?f=pathology) ## Elsewhere in DurgiPedia - [Maternal physiological changes in pregnancy](https://durgical.com/en/physiology/maternal-physiological-changes-in-pregnancy/) - [Placenta: structure, circulation and functions](https://durgical.com/en/embryology/placenta-structure-circulation-and-functions/) - [The placenta and pregnancy hormones](https://durgical.com/en/physiology/the-placenta-and-pregnancy-hormones/) - [Placenta](https://durgical.com/en/histology/placenta/) ## Connections ## Related 10 - [The placenta in late pregnancy](https://durgical.com/en/general-pathology/the-placenta-in-late-pregnancy/) - [Placenta previa and placenta accreta spectrum](https://durgical.com/en/general-pathology/placenta-previa-and-placenta-accreta-spectrum/) - [Hydatidiform mole: complete vs partial](https://durgical.com/en/general-pathology/hydatidiform-mole-complete-vs-partial/) - [Liver disease in pregnancy](https://durgical.com/en/general-pathology/liver-disease-in-pregnancy/) - [Thrombotic microangiopathy: the kidney](https://durgical.com/en/general-pathology/thrombotic-microangiopathy-the-kidney/) - [Thrombotic microangiopathies: TTP vs HUS](https://durgical.com/en/general-pathology/thrombotic-microangiopathies-ttp-vs-hus/) - [Tumour angiogenesis](https://durgical.com/en/general-pathology/tumour-angiogenesis/) - [Edema and effusions: the four mechanisms](https://durgical.com/en/general-pathology/edema-and-effusions-the-four-mechanisms/) - [Disseminated intravascular coagulation: how consumption causes both clots and bleeding](https://durgical.com/en/general-pathology/disseminated-intravascular-coagulation-how-consumption-causes-both-clots-and-ble/) - [Infarction: red vs white, and what decides the damage](https://durgical.com/en/general-pathology/infarction-red-vs-white-and-what-decides-the-damage/) ## Related conditions 8 - [Preeclampsia](https://durgical.com/en/conditions/preeclampsia/) - [Eclampsia](https://durgical.com/en/conditions/eclampsia/) - [HELLP syndrome](https://durgical.com/en/conditions/hellp-syndrome/) - [Fetal growth restriction](https://durgical.com/en/conditions/fetal-growth-restriction/) - [Placental abruption](https://durgical.com/en/conditions/placental-abruption/) - [Disseminated intravascular coagulation](https://durgical.com/en/conditions/disseminated-intravascular-coagulation/) - [Arterial hypertension](https://durgical.com/en/conditions/arterial-hypertension/) - [Stillbirth (intrauterine fetal death)](https://durgical.com/en/conditions/stillbirth/) [← All of general pathology](https://durgical.com/en/general-pathology/) Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given. Sources: [Preeclampsia](https://www.ncbi.nlm.nih.gov/books/NBK570611/) (StatPearls (NCBI Bookshelf), 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/general-pathology/preeclampsia-and-eclampsia/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/preeclampsia-and-eclampsia/