Management of Pre-eclampsia and Eclampsia

RCOG has retired this as a standalone Green-top guideline — current UK guidance on hypertension in pregnancy, including pre-eclampsia and eclampsia, is NICE NG133 (2023). Retained here for the detailed eclampsia/severe pre-eclampsia management algorithm below, which remains accurate and exam-relevant; cross-check against NICE NG133 for current diagnostic thresholds.

Definitions

• Chronic hypertension: hypertension present before 20 weeks gestation or pre-existing
• Gestational hypertension: new hypertension after 20 weeks without proteinuria or other features
• Pre-eclampsia: new hypertension after 20 weeks with significant proteinuria (urine PCR ≥30 mg/mmol) OR other maternal organ dysfunction
• Superimposed pre-eclampsia: chronic hypertension with new proteinuria or other features after 20 weeks
• Eclampsia: generalised tonic-clonic seizures in the context of pre-eclampsia
• HELLP syndrome: Haemolysis, Elevated Liver enzymes, Low Platelets

Blood Pressure Thresholds

• Mild hypertension: 140-149/90-99 mmHg
• Moderate hypertension: 150-159/100-109 mmHg
• Severe hypertension: ≥160/110 mmHg — requires urgent treatment

Risk Factors for Pre-eclampsia

High risk (aspirin prophylaxis indicated if any ONE)

• Previous pre-eclampsia
• Chronic kidney disease
• Autoimmune conditions (SLE, antiphospholipid syndrome)
• Type 1 or type 2 diabetes
• Chronic hypertension

Moderate risk (aspirin if TWO or more)

• First pregnancy
• Age ≥40
• BMI ≥35
• Family history of pre-eclampsia
• Multiple pregnancy
• Inter-pregnancy interval >10 years

Prevention

• Aspirin 150mg daily from 12 weeks to 36 weeks (taken at bedtime) for high-risk women
• Calcium supplementation if dietary intake is low (<600mg/day)

Investigations

• Blood tests: FBC (platelets), U&E (creatinine, urea), LFTs (ALT, AST), uric acid, coagulation screen
• Urine: spot urine protein:creatinine ratio (PCR ≥30 mg/mmol confirms significant proteinuria), or 24-hour urine collection (≥300mg/24h)
• PlGF-based testing: placental growth factor — low PlGF (<100 pg/ml) or sFlt-1:PlGF ratio helps rule in/out pre-eclampsia (NICE recommended from 20 weeks)
• Fetal assessment: USS for growth, amniotic fluid, umbilical artery Doppler

Antihypertensive Treatment

• Target BP: <135/85 mmHg (NICE NG133)
• Treat moderate hypertension (≥150/100) — do not wait for severe threshold

Magnesium Sulphate

• Indication: prevention/treatment of eclamptic seizures in severe pre-eclampsia
• MAGPIE trial: halved the risk of eclampsia in women with severe pre-eclampsia
• Loading dose: 4g IV over 5-15 minutes
• Maintenance: 1g/hour IV infusion for 24 hours
• Therapeutic range: 2-4 mmol/L
• Toxicity monitoring (check hourly): respiratory rate (>16/min), deep tendon reflexes (present), urine output (>25ml/hr)
• Toxicity sequence: loss of reflexes → respiratory depression → cardiac arrest
• Antidote: 10ml of 10% calcium gluconate IV

Timing of Delivery

• <34 weeks with severe features: stabilise, corticosteroids, deliver if condition deteriorates
• 34-36+6 weeks: deliver if pre-eclampsia with severe features
• 37+ weeks: recommend delivery for all women with pre-eclampsia
• Eclampsia or uncontrolled severe hypertension: stabilise and deliver regardless of gestation

Postpartum Management

• Monitor BP for minimum 72 hours after delivery
• Enalapril is first-line postnatally (safe in breastfeeding)
• Stop methyldopa within 2 days of delivery
• Continue monitoring for at least 6 weeks
• Long-term cardiovascular risk: inform women that pre-eclampsia doubles lifetime cardiovascular disease risk

Important Facts for MRCOG

• Pre-eclampsia = hypertension + proteinuria (or other organ dysfunction) after 20 weeks
• Aspirin 150mg at bedtime from 12 weeks for high-risk women
• Labetalol is first-line antihypertensive (contraindicated in asthma)
• MAGPIE trial: magnesium sulphate halves eclampsia risk
• Magnesium toxicity: loss of reflexes → respiratory depression → cardiac arrest; antidote = calcium gluconate
• HELLP syndrome: haemolysis, elevated liver enzymes, low platelets — variant of severe pre-eclampsia
• PlGF testing aids diagnosis from 20 weeks
• Pre-eclampsia doubles lifetime cardiovascular disease risk

Source: RCOG Green-top Guideline No. 10A (Archived) (2010 (RCOG archived; superseded by NICE NG133, 2023))

Read the original on rcog.org.uk

Clinically reviewed by NHS obstetricians and gynaecologists · Source last updated 2010 (RCOG archived; superseded by NICE NG133, 2023)

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