🤰 Obstetrics

Pre-eclampsia

Pregnancy-specific multisystem disorder defined by new hypertension and organ dysfunction — a leading cause of maternal and perinatal death.

Overview

Pre-eclampsia complicates 2–8% of pregnancies. It arises from abnormal placentation, with widespread maternal endothelial dysfunction. It can present at any gestation ≥20 weeks and into the puerperium. Magnesium sulfate and timely delivery remain the cornerstones; aspirin prophylaxis halves risk in high-risk women.

Symptoms

  • Often asymptomatic — detected on routine BP/urine check
  • Severe headache, visual disturbance, flashing lights
  • Right upper quadrant or epigastric pain
  • Sudden swelling of face, hands or feet
  • Reduced fetal movements

Risk factors

  • Previous pre-eclampsia, chronic hypertension, chronic kidney disease, diabetes, autoimmune disease (SLE, APS)
  • First pregnancy, age ≥40, BMI ≥35, multiple pregnancy
  • Family history (mother/sister)
  • IVF, interval >10 years between pregnancies

Causes

  • Abnormal trophoblast invasion of spiral arteries → placental ischaemia
  • Release of anti-angiogenic factors (sFlt-1, soluble endoglin)
  • Maternal endothelial dysfunction

🚨 Red flags — seek urgent care

  • BP ≥160/110, severe headache, visual disturbance, RUQ pain
  • Convulsions (eclampsia)
  • Falling platelets, rising transaminases, deranged renal function (HELLP)
  • Placental abruption
  • Reduced fetal movements or abnormal CTG

When to seek care

  • Severe persistent headache, visual change, epigastric pain — same-day assessment
  • BP ≥140/90 at home — contact maternity
  • Reduced fetal movements at any time

Diagnosis

  • New-onset hypertension (≥140/90) after 20 weeks, AND
  • Proteinuria (≥30 mg/mmol PCR or 300 mg/24h), or organ dysfunction (renal, hepatic, neurological, haematological), or uteroplacental dysfunction (IUGR, abnormal Doppler)
  • PlGF / sFlt-1:PlGF ratio aids diagnosis and rule-out (NICE DG23)
  • Bloods: FBC, U&E, LFTs, urate, coagulation

Treatment

  • Antihypertensive: labetalol first-line (nifedipine MR if asthmatic; methyldopa as alternative)
  • Magnesium sulfate (4 g IV bolus then 1 g/hour) for severe pre-eclampsia or eclampsia — prevents/treats seizures
  • Antenatal corticosteroids 24–34 weeks, magnesium sulfate <30 weeks for neuroprotection
  • Plan delivery: ≥37 weeks recommended; earlier for severe disease/maternal-fetal compromise
  • Continuous BP and bloods monitoring during/after delivery
  • Postnatal antihypertensives often required for weeks — BP can peak day 3–5 postpartum

Prevention

  • Aspirin 75–150 mg daily from 12 weeks until birth in high-risk women (one major or two moderate risk factors)
  • Calcium supplementation in low-calcium-intake populations
  • Optimise BP, weight and chronic conditions pre-pregnancy

Complications

  • Eclampsia, stroke, HELLP syndrome, DIC
  • Placental abruption, IUGR, preterm birth, stillbirth
  • Pulmonary oedema, AKI, liver haematoma/rupture
  • Long-term: doubled lifetime cardiovascular risk

Prognosis

Most women recover fully postpartum but require careful BP follow-up. Long-term cardiovascular risk is doubled — lifestyle and BP surveillance matter for decades.

Education & self-care

Know the warning signs: severe headache, visual changes, upper abdominal pain, sudden swelling, or reduced fetal movements. Acting fast saves lives.

Frequently asked questions

Will I get pre-eclampsia again?

Recurrence is around 15–20%, higher with early-onset/severe disease. Aspirin from 12 weeks reduces risk.

Is delivery the only cure?

Yes — pre-eclampsia resolves after the placenta is delivered, though postpartum BP control is still essential.

Does mild hypertension matter?

Yes — it can progress quickly. All new pregnancy hypertension needs urgent assessment.

Medically reviewed by Dr. Handel Emery, MD, FRCP (UK) · Last reviewed 2026-06-08