Pre-eclampsia Summary

Definitions

  • Hypertension: BP ≥140/90 mmHg
  • Severe HTN: BP ≥160/110 mmHg
  • Pre-eclampsia: HTN + proteinuria/organ dysfunction after 20 weeks
  • Eclampsia: Seizures in pre-eclampsia

High Risk Factors

  • Previous hypertensive pregnancy
  • Chronic kidney disease
  • Autoimmune disease
  • Diabetes
  • Chronic hypertension

Key Symptoms

  • Severe headaches
  • Visual disturbances
  • Epigastric/RUQ pain
  • Vomiting
  • Sudden swelling

Management

  • Prevention: Aspirin 75-150mg from 12 weeks
  • Mild HTN: Labetalol first-line
  • Severe HTN: IV labetalol/hydralazine
  • Seizures: Magnesium sulfate

Investigations

  • Urine protein:creatinine ratio
  • FBC, LFTs, U&Es
  • Platelet count
  • Regular BP monitoring

Fetal Monitoring

  • Growth scans
  • Umbilical artery Doppler
  • CTG monitoring

Complications

  • Eclampsia
  • HELLP syndrome
  • Renal/liver failure
  • Placental abruption
  • Fetal growth restriction

Pre-eclampsia

A multi-system disorder of pregnancy characterized by hypertension and organ dysfunction

Definitions

Hypertension in pregnancy is defined as diastolic BP ≥ 90 mmHg and/or systolic BP ≥ 140 mmHg.

Severe Hypertension

Diastolic BP ≥ 110 mmHg and/or systolic BP ≥ 160 mmHg

Gestational Hypertension

New hypertension presenting after 20 weeks' gestation without significant proteinuria

Pre-eclampsia

New hypertension after 20 weeks + proteinuria or other maternal organ dysfunction

Pre-eclampsia Diagnostic Criteria

Pre-eclampsia requires new hypertension after 20 weeks gestation PLUS one or more of:

Proteinuria

Significant protein in urine

Renal Insufficiency

Creatinine ≥ 90 μmol/L (≥ 1.02 mg/dL)

Liver Involvement

Elevated transaminases (> 40 IU/L) ± abdominal pain

Neurological Complications

Eclampsia, altered mental status, blindness, stroke, severe headaches

Haematological Complications

Thrombocytopenia (< 150,000/μL), DIC, haemolysis

Uteroplacental Dysfunction

Fetal growth restriction, abnormal Doppler, stillbirth

Severe Forms

HELLP Syndrome

  • Haemolysis
  • Elevated Liver enzymes
  • Low Platelets

Severe form with high maternal and perinatal morbidity/mortality

Eclampsia

Occurrence of one or more seizures in a woman with pre-eclampsia

Risk Factors

High Risk Factors (One required)

  • History of hypertensive disease during previous pregnancy
  • Chronic kidney disease
  • Autoimmune disease (SLE, antiphospholipid syndrome)
  • Type 1 or type 2 diabetes
  • Chronic hypertension

Moderate Risk Factors (Two or more required)

Demographic

  • First pregnancy
  • Aged ≥ 40 years
  • BMI ≥ 35 kg/m²
  • Family history of pre-eclampsia

Obstetric

  • Pregnancy interval > 10 years
  • Multiple pregnancy

Clinical Features

Advise immediate medical review if any of these symptoms develop

Neurological

  • Severe headaches (unrelieved by analgesics)
  • Visual disturbances
  • Blurred vision, flashing lights
  • Persistent visual scotomata

Gastrointestinal

  • Persistent epigastric pain
  • Right upper quadrant pain
  • Vomiting
  • Nausea

Other Symptoms

  • Breathlessness
  • Sudden swelling of face, hands, feet
  • Reduced fetal movements

Complications

Maternal Complications

Neurological

  • Eclamptic seizures
  • Intracranial haemorrhage
  • Cerebral infarction
  • Cerebral oedema

Organ Failure

  • Acute renal failure
  • Liver dysfunction/rupture
  • Hepatic failure/necrosis

Other Systems

  • Coagulation abnormalities
  • ARDS and pulmonary oedema
  • Death

Fetal Complications

Placental

  • Placental abruption
  • Uteroplacental insufficiency

Fetal

  • Intrauterine growth restriction (IUGR)
  • Preterm delivery
  • Stillbirth
  • Neonatal death

Management

Prevention

For women at high risk: Aspirin 75-150 mg daily from 12 weeks gestation until birth

Monitoring & Screening

Routine Antenatal Care
  1. Dipstick urine for protein at each visit
  2. Measure blood pressure at each visit
  3. Assess for symptoms of pre-eclampsia
  4. If dipstick 1+ or more:
    Use albumin:creatinine ratio (≥8 mg/mmol) or
    Protein:creatinine ratio (≥30 mg/mmol)

Blood Pressure Management

BP 140/90 - 159/109 mmHg

  • Admit if clinical concerns
  • Offer pharmacological treatment if BP remains elevated
  • Target BP ≤ 135/85 mmHg
  • BP monitoring every 48 hours
  • FBC, LFTs, U&Es twice weekly

BP ≥ 160/110 mmHg

  • Admit to hospital
  • Pharmacological treatment for all women
  • Target BP ≤ 135/85 mmHg
  • BP every 15-30 minutes until < 160/110 mmHg
  • FBC, LFTs, U&Es 3 times weekly

Antihypertensive Therapy

Medication Indication Notes
Labetalol First-line treatment Oral or intravenous
Nifedipine Second-line if labetalol unsuitable Oral preparation
Methyldopa Third-line option If labetalol/nifedipine not suitable
Hydralazine Severe hypertension in critical care Intravenous administration

Magnesium Sulfate Protocol

Indications for magnesium sulfate:

  • Eclampsia or previous eclamptic fit
  • Severe pre-eclampsia with birth planned within 24 hours
  • Features of severe pre-eclampsia:
    Ongoing severe headaches/visual scotomata
    Nausea/vomiting/epigastric pain
    Oliguria and severe hypertension
    Deteriorating blood tests
Magnesium Sulfate Regimen
  1. Loading dose: 4 g IV over 5-15 minutes
  2. Maintenance: 1 g/hour infusion for 24 hours
  3. After eclampsia: Continue for 24 hours after last fit
  4. Recurrent fits: Additional 2-4 g IV over 5-15 minutes

Do not use diazepam, phenytoin or other anticonvulsants as alternatives to magnesium sulfate in eclampsia.