What are the guidelines for managing preeclampsia?

Guidelines for Managing Preeclampsia

The management of preeclampsia requires early risk assessment, regular monitoring, and timely intervention to prevent maternal and fetal morbidity and mortality. 1

Definition and Diagnosis

Preeclampsia is defined as:

• New hypertension (BP ≥140/90 mmHg) after 20 weeks gestation
• With proteinuria (≥30 mg/mmol or 0.3 mg/mg protein/creatinine ratio) 1

Alternative diagnostic criteria include hypertension with any of these features:

• Maternal organ dysfunction
• Uteroplacental dysfunction 2

Risk Assessment and Prevention

Risk Factors

• Previous preeclampsia (RR 7.19) 3
• Presence of antiphospholipid antibodies (RR 9.72) 3
• Pre-existing diabetes (RR 3.56) 3
• Multiple pregnancy (RR 2.93) 3
• Nulliparity (RR 2.91) 3
• Family history of preeclampsia (RR 2.90) 3
• Advanced maternal age ≥40 years (RR 1.68-1.96) 3
• BMI ≥35 (RR 1.55) 3
• Pre-existing hypertension or booking diastolic BP ≥90 mmHg 3
• Pre-existing renal disease or booking proteinuria 3

Prevention

• Low-dose aspirin (81 mg/day) should be initiated between 12-16 weeks of gestation and continued until delivery for high-risk women, reducing preeclampsia risk by 24% 1
• Calcium supplementation (1.0-1.5g daily) for women with low calcium intake 1
• Dietary modifications focusing on fruits, vegetables, and whole grains 1
• Regular exercise following established guidelines 1

Monitoring and Surveillance

For Women at Low Risk

• Blood pressure and urine dipstick testing at each antenatal visit 3

For Women at High Risk

• Offer referral before 20 weeks for specialist input if they have:
  • Previous preeclampsia
  • Multiple pregnancy
  • Pre-existing hypertension, renal disease, or diabetes
  • Presence of antiphospholipid antibodies
  • Any two other risk factors 3

After 20 Weeks

• Monitor for signs and symptoms of preeclampsia:
  • New hypertension
  • New proteinuria
  • Symptoms of headache, visual disturbances, epigastric pain 3
  • Fetal compromise 3

Laboratory Monitoring

Regular assessment of:

• Complete blood count with platelets
• Liver function tests
• Renal function
• Uric acid
• Fibrinogen levels (to evaluate for potential DIC) 1

Management of Preeclampsia

Non-Severe Preeclampsia

• First-line oral agents:
  • Methyldopa
  • Labetalol 1
• Target blood pressure: diastolic 85 mmHg, systolic 110-140 mmHg 1
• Close maternal and fetal monitoring 4

Severe Preeclampsia

• Hospitalization for close monitoring 4

• First-line IV medications for severe hypertension:

  • Labetalol: Initial dose 10-20 mg, then 20-80 mg every 10-30 minutes (maximum 300 mg)
  • Hydralazine: 5-10 mg every 15-30 minutes (maximum 30 mg)
  • Nifedipine 1

• Magnesium sulfate for seizure prophylaxis:

  • Initial dose: 4-5g IV in 250 mL of 5% Dextrose or 0.9% Sodium Chloride over 3-4 minutes
  • Maintenance: 1-2g/hour by constant IV infusion
  • Continue until 24 hours postpartum
  • Target serum magnesium level: 6 mg/100 mL
  • Maximum daily dose: 30-40g 5

Fetal Monitoring

• Continuous fetal heart rate monitoring
• Ultrasound for fetal growth assessment
• Amniotic fluid volume assessment
• Doppler studies if growth restriction is suspected 1

Delivery Considerations

Indications for Delivery

• Gestational age ≥37 weeks
• Severe features at 34-37 weeks
• Repeated episodes of severe hypertension despite treatment
• HELLP syndrome (immediate delivery regardless of gestational age) 1

Preparation for Delivery

• Administer corticosteroids for fetal lung maturation if delivery anticipated between 24-34 weeks 1
• Platelet transfusion if count <50,000/mm³, especially prior to Caesarean section 1
• Whole blood or packed red cells if hemoglobin <10 g/dL 1

Postpartum Care

• Continue blood pressure monitoring every 4-6 hours for at least 3 days
• Taper antihypertensive medications slowly after days 3-6
• Follow-up within 1 week if still on antihypertensives at discharge 1
• Prescribe automated home blood pressure monitoring devices 1

Common Pitfalls and Caveats

• ACE inhibitors are contraindicated during pregnancy 1
• Diuretics are generally not recommended as first-line therapy as they reduce plasma volume expansion 1
• Continuous use of magnesium sulfate in pregnancy beyond 5-7 days can cause fetal abnormalities 5
• In severe renal insufficiency, maximum dosage of magnesium sulfate is 20g/48 hours with frequent serum magnesium monitoring 5
• Vitamin C and E supplements are not recommended for prevention 1

By following these guidelines, clinicians can effectively manage preeclampsia to optimize maternal and fetal outcomes.