What is the management approach for a pregnant patient diagnosed with preeclampsia?

Management of Preeclampsia

Deliver the patient immediately after maternal stabilization if gestational age is ≥37 weeks, or if severe features are present at ≥34 weeks. 1, 2, 3

Initial Assessment and Diagnosis Confirmation

• Confirm preeclampsia by documenting blood pressure ≥140/90 mmHg on repeat measurements at least 15 minutes apart while the patient is seated with legs uncrossed, back supported, and arm at heart level 4, 1
• Assess for proteinuria using spot urine protein/creatinine ratio (≥30 mg/mmol or ≥0.3 mg/mg is abnormal), 24-hour urine collection (≥300 mg/24 hours), or dipstick (≥1+) 1, 2
• Note that proteinuria is no longer mandatory for diagnosis—preeclampsia can be diagnosed with new-onset hypertension after 20 weeks plus evidence of end-organ dysfunction even without proteinuria 2, 5

Severity Classification: Identify Severe Features Immediately

Severe features requiring urgent intervention include: 1, 2

• Severe hypertension: BP ≥160/110 mmHg on two occasions at least 15 minutes apart
• Thrombocytopenia: platelets <100,000/μL
• Renal dysfunction: creatinine >1.1 mg/dL or doubling of baseline
• Liver dysfunction: transaminases elevated to twice normal values
• Pulmonary edema
• New-onset severe persistent headache, visual disturbances (scotomata, cortical blindness), or epigastric/right upper quadrant pain

Urgent Blood Pressure Management for Severe Hypertension

When BP ≥160/110 mmHg persists for >15 minutes, initiate urgent antihypertensive therapy immediately to prevent maternal cerebral hemorrhage. 1, 2

• Target blood pressure: systolic 110-140 mmHg and diastolic 85 mmHg 1, 2
• First-line IV options: 2, 6
  • IV labetalol: 20 mg IV bolus, then 40 mg after 10 minutes, then 80 mg every 10 minutes (maximum cumulative dose 220 mg)
  • IV hydralazine: 5-10 mg IV every 20 minutes as needed
• First-line oral option for non-severe hypertension (140-159/90-109 mmHg): oral nifedipine 1, 2
• Critical contraindications: Never use ACE inhibitors, ARBs, or direct renin inhibitors due to severe fetotoxicity causing renal dysgenesis 1
• Avoid diuretics—they further reduce plasma volume which is already contracted in preeclampsia and worsen uteroplacental perfusion 1, 2

Magnesium Sulfate for Seizure Prophylaxis

Administer magnesium sulfate immediately if severe features are present, or if the patient has proteinuria with severe hypertension (≥160/110 mmHg), or any neurological symptoms (headache, visual changes). 1, 2, 3, 6

• Loading dose: 4-5 g IV over 5 minutes (diluted in 250 mL of 5% dextrose or 0.9% normal saline) 2, 6
• Maintenance: 1-2 g/hour continuous IV infusion 2, 6
• Alternative regimen: 4-5 g IV loading dose followed by 4-5 g IM into alternate buttocks every 4 hours 6
• Monitor patellar reflexes before each dose—if absent, hold magnesium until reflexes return 6
• Ensure urine output ≥100 mL in the 4 hours preceding each dose 6
• Do not continue magnesium sulfate beyond 5-7 days as it can cause fetal skeletal abnormalities including hypocalcemia, skeletal demineralization, and osteopenia 6
• Keep IV calcium gluconate immediately available to counteract magnesium toxicity 6

Comprehensive Laboratory Assessment

Obtain baseline laboratory tests and repeat at least twice weekly or more frequently if clinical deterioration occurs: 1, 2, 3

• Complete blood count with focus on hemoglobin and platelet count
• Comprehensive metabolic panel: liver transaminases (AST/ALT), creatinine, uric acid
• Spot urine protein/creatinine ratio

Fetal Surveillance

• Initiate serial ultrasound assessments for fetal biometry, amniotic fluid volume, and umbilical artery Doppler to monitor for intrauterine growth restriction 1
• Perform continuous electronic fetal heart rate monitoring to assess fetal well-being 1, 3
• Conduct biophysical profile including assessment of fetal breathing movements, body movements, and tone 3

Delivery Timing: Gestational Age-Based Algorithm

≥37 weeks gestation: 2, 3

• Deliver immediately after maternal stabilization regardless of severity
• Do not delay delivery based on non-reactive NST—delivery is indicated at this gestational age regardless of fetal testing results

34-37 weeks gestation: 1, 2

• Without severe features: expectant management with close monitoring is appropriate
• With severe features: deliver after maternal stabilization

<34 weeks gestation: 2, 7

• Administer antenatal corticosteroids to promote fetal lung maturity
• Consider expectant management in select patients between 24-34 weeks with severe preeclampsia in a hospital with maternal intensive care and neonatal intensive care capabilities
• Expectant management at <24 weeks is associated with high maternal morbidity with limited perinatal benefit

Absolute Indications for Immediate Delivery (Any Gestational Age)

Deliver immediately regardless of gestational age if any of the following develop: 1, 2

• Eclamptic seizures
• Inability to control BP despite ≥3 classes of antihypertensives in appropriate doses
• Progressive thrombocytopenia or progressively abnormal liver or renal function tests
• Pulmonary edema (treat with IV nitroglycerin starting at 5 mcg/min, gradually increased every 3-5 minutes to maximum 100 mcg/min) 2
• Severe intractable headache or repeated visual scotomata
• Placental abruption
• Non-reassuring fetal status on continuous monitoring
• Maternal oxygen saturation deterioration (<90%)

HELLP Syndrome Recognition

• HELLP syndrome is defined by hemolysis, elevated liver enzymes (AST/ALT >2x normal), and low platelets (<100,000/μL) 2, 5
• Epigastric or right upper quadrant pain is a hallmark symptom 1, 2
• Maternal mortality rate is 3.4% 2
• Monitor glucose intraoperatively as severe hypoglycemia can occur 2

Mode of Delivery and Anesthesia

• Prefer vaginal delivery unless cesarean is indicated for standard obstetric reasons 3
• Neuraxial analgesia and anesthesia are strongly preferred as first-line anesthetic techniques in the absence of thrombocytopenia 5, 8
• Carefully evaluate coagulation status before neuraxial anesthesia 8

Critical Pitfalls to Avoid

• Do not underestimate disease severity based on "mild" classification—all preeclampsia can rapidly progress to life-threatening emergencies 2, 3
• Blood pressure level alone is not a reliable indicator of disease severity—serious organ dysfunction can develop at relatively mild blood pressure elevations 1, 2
• Do not use serum uric acid level or degree of proteinuria as indications for delivery 1, 2
• Do not delay delivery at ≥37 weeks based on non-reactive NST—delivery is indicated regardless of fetal testing results 2, 3
• Do not reduce antihypertensives if diastolic BP falls <80 mmHg 2
• Do not use NSAIDs for analgesia if delivery occurs, as they can worsen renal function in preeclampsia 1
• Do not use low molecular weight heparin for prevention—it is not indicated even with prior early-onset preeclampsia 1
• Do not use plasma volume expansion routinely for pulmonary edema 2

Hospital Setting Requirements

• Management must occur in a hospital with appropriate obstetrical care facilities, maternal intensive care capabilities, and neonatal intensive care unit for extremely premature infants 1
• Coordinate care with maternal-fetal medicine specialists, neonatology, and anesthesiology teams 1