What is the management of pre-eclampsia?

Management of Pre-eclampsia

The management of pre-eclampsia requires urgent blood pressure control when severe (≥160/110 mmHg), magnesium sulfate for seizure prophylaxis in severe cases, and delivery at 37 weeks or earlier if complications develop. 1, 2

Diagnosis and Assessment

• Pre-eclampsia is defined as gestational hypertension (≥140/90 mmHg) accompanied by one or more of: proteinuria (>0.3 g/24h or ACR ≥30 mg/mmol), evidence of maternal organ dysfunction, or uteroplacental dysfunction 1
• All women with pre-eclampsia should undergo comprehensive maternal monitoring including:
  • Blood pressure monitoring at least every 4-6 hours 2
  • Proteinuria assessment (urine protein/creatinine ratio ≥30 mg/mmol is abnormal) 1
  • Clinical assessment for clonus and other neurological signs 2
  • At least twice weekly blood tests for hemoglobin, platelet count, liver enzymes, and renal function tests 1, 2
• Fetal monitoring should include initial assessment of fetal well-being with ultrasound evaluation of fetal growth, amniotic fluid, and umbilical artery Doppler 2

Blood Pressure Management

• Severe hypertension (≥160/110 mmHg) requires urgent treatment in a monitored setting 1
• First-line medications for severe hypertension include:
  • Oral nifedipine
  • Intravenous labetalol
  • Intravenous hydralazine 1, 2
• For BP consistently ≥140/90 mmHg, treatment should aim for a target diastolic BP of 85 mmHg and systolic BP between 110-140 mmHg 1
• First-line oral antihypertensives for non-severe hypertension include methyldopa, labetalol, oxprenolol, and nifedipine 1, 2
• Antihypertensive drugs should be reduced or ceased if diastolic BP falls below 80 mmHg 1, 2

Seizure Prevention

• Magnesium sulfate is the drug of choice for prevention and treatment of seizures in pre-eclampsia 1, 3
• Indications for magnesium sulfate administration include:
  • Pre-eclampsia with severe hypertension
  • Pre-eclampsia with neurological signs or symptoms 1
• Dosing regimen for magnesium sulfate:
  • Loading dose: 4-5g IV over 15-20 minutes
  • Maintenance: 1-2g/hour continuous infusion or 5g IM every 4 hours 3, 2
  • Continue for 24 hours postpartum 2
• Monitor for magnesium toxicity by assessing patellar reflexes, respiratory rate, and urine output 3
• Therapeutic serum magnesium level for seizure control is approximately 6 mg/100 mL 3

Delivery Considerations

• Women with pre-eclampsia should be delivered if they have reached 37 weeks' gestation 1, 2
• Earlier delivery is indicated for any of the following complications:
  • Repeated episodes of severe hypertension despite treatment with multiple antihypertensive agents 1
  • Progressive thrombocytopenia 1, 2
  • Progressively abnormal renal or liver enzyme tests 1, 2
  • Pulmonary edema 1, 2
  • Abnormal neurological features (severe headache, visual disturbances, eclampsia) 1, 2
  • Non-reassuring fetal status 1
• Between 24-34 weeks, antenatal corticosteroids should be administered to promote fetal lung maturity if delivery is anticipated 4

Postpartum Management

• Continue close monitoring for at least 72 hours postpartum as 10% of maternal deaths due to hypertensive disorders occur in the postpartum period 1, 2
• Continue magnesium sulfate for 24 hours after delivery 2
• Monitor blood pressure at least every 4-6 hours for at least 3 days 2
• Antihypertensives should be continued postpartum and tapered slowly only after days 3-6 unless BP becomes low (<110/70 mmHg) 2

Special Considerations

• Women with pre-eclampsia should be assessed in hospital when first diagnosed; some may be managed as outpatients once their condition is stabilized 1
• Avoid NSAIDs for analgesia as they may worsen hypertension and renal function 1, 2
• Limit fluid intake to 60-80 mL/hour to prevent pulmonary edema; plasma volume expansion is not recommended 2
• The combination of calcium channel blockers with magnesium sulfate may cause myocardial depression, requiring close cardiac monitoring 2
• Women with pre-eclampsia should be managed at centers with adequate maternal and neonatal intensive care resources, especially if onset is before 34 weeks' gestation 1, 2

Common Pitfalls to Avoid

• Do not classify pre-eclampsia as mild versus severe as all cases can rapidly deteriorate 2
• Do not delay treatment of severe hypertension (≥160/110 mmHg) as it can lead to cerebrovascular accidents 1
• Do not use diuretics routinely as they may worsen placental perfusion 2
• Do not exceed total daily dose of 30-40g of magnesium sulfate in 24 hours; maximum dose is 20g/48h in severe renal insufficiency 3
• Do not continue magnesium sulfate beyond 5-7 days as it can cause fetal abnormalities 3