Pre-eclampsia
A placental disorder of pregnancy in which anti-angiogenic factors injure maternal endothelium, producing new hypertension with proteinuria or organ dysfunction after 20 weeks, curable only by delivery.
In a nutshell
A shallowly implanted placenta becomes ischaemic and releases anti-angiogenic factors that mop up VEGF and placental growth factor, injuring maternal endothelium everywhere. New hypertension with proteinuria or organ dysfunction after 20 weeks follows. Only delivery cures it.
Classic presentation
New hypertension after 20 weeks' gestation with significant proteinuria; when severe, a frontal headache, visual disturbance, epigastric pain, brisk reflexes and clonus.
Key points
- VEGF withdrawal hits the most fenestrated endothelia hardest, which predicts the syndrome: podocyte injury in the glomerulus (proteinuria), lost nitric-oxide vasodilatation (hypertension), and liver and brain involvement.
- It is defined after 20 weeks' gestation. Hypertension before that is chronic hypertension, not pre-eclampsia.
- Antihypertensives protect the maternal brain and heart. They do nothing to the placental cause.
- Magnesium sulfate prevents and treats eclamptic seizures as a neuronal membrane stabiliser. It is not an antihypertensive.
- Delivery is the only cure, because it removes the source of anti-angiogenic factors. Its timing balances maternal risk against fetal prematurity.
- Low-dose aspirin from early in the second trimester reduces incidence in women at high risk.
- The same placental insufficiency restricts fetal growth, so fetal wellbeing is monitored alongside the mother.
First-line investigation
Blood pressure with urinary protein quantification (PCR or ACR), plus FBC, U&E, LFTs and urate to detect the multi-organ endothelial injury.
First-line management
Treat severe hypertension promptly to protect the mother, give magnesium sulfate where seizure risk is high, and plan the timing of delivery with senior obstetric input.
Exam traps
- Magnesium sulfate is for seizures, not for blood pressure. When the stem asks how to lower the pressure, magnesium is the distractor.
- HELLP syndrome can present with epigastric pain and deranged liver enzymes before the blood pressure looks alarming.
- Pre-eclampsia is often entirely asymptomatic and found on routine screening. The absence of symptoms does not reassure.
Educational content pending clinical review. Not medical advice.