What are the management guidelines for a pregnant woman with preeclampsia?

Management of Preeclampsia

All women with preeclampsia at ≥37 weeks' gestation should be delivered immediately after maternal stabilization, regardless of disease severity, while those with severe features at any gestational age require urgent blood pressure control with antihypertensives, magnesium sulfate for seizure prophylaxis, and delivery planning based on specific maternal and fetal indications. 1

Initial Diagnosis and Severity Assessment

Diagnostic Criteria

• Preeclampsia is defined as new-onset hypertension (BP ≥140/90 mmHg) after 20 weeks' gestation, and proteinuria is no longer mandatory for diagnosis 1, 2
• When proteinuria is present, confirm with spot urine protein/creatinine ratio ≥30 mg/mmol (or 0.3 mg/mg), ≥300 mg/24 hours, or ≥1+ on dipstick 1
• Preeclampsia rarely occurs before 20 weeks except with trophoblastic disease (hydatidiform mole), so consider alternative diagnoses in early presentations 3

Severe Features Requiring Immediate Action

• Severe hypertension: BP ≥160/110 mmHg on two occasions at least 15 minutes apart 1
• Thrombocytopenia: platelets <100,000/μL 1
• Renal dysfunction: creatinine >1.1 mg/dL or doubling of baseline 1
• Liver dysfunction: transaminases ≥2× upper limit of normal 1
• Pulmonary edema 1, 2
• Neurological symptoms: severe persistent headache, visual disturbances (scotomata, cortical blindness), or right upper quadrant/epigastric pain 3, 1

Critical Pitfall: Do not rely on blood pressure level alone to determine disease severity—serious organ dysfunction can develop at relatively mild blood pressure elevations 3, 1, 2

Immediate Stabilization for Severe Hypertension

Blood Pressure Management

• Initiate urgent antihypertensive therapy within 15 minutes when BP ≥160/110 mmHg persists to prevent maternal cerebral hemorrhage 3, 1
• Target systolic BP 110-140 mmHg and diastolic BP 85 mmHg (or at minimum <160/105 mmHg) 3, 1, 2

First-Line Antihypertensive Options

• Oral nifedipine is the preferred first-line agent 3
• IV labetalol: 20 mg IV bolus, then 40 mg after 10 minutes, then 80 mg every 10 minutes (maximum cumulative dose 220 mg) 1
• IV hydralazine: 5-10 mg IV every 20 minutes as needed 1

Critical Contraindications:

• Never use ACE inhibitors, ARBs, or direct renin inhibitors due to severe fetotoxicity causing renal dysgenesis 3
• Avoid diuretics as they further reduce plasma volume, which is already compromised in preeclampsia and worsens uteroplacental perfusion 3, 1

Magnesium Sulfate for Seizure Prophylaxis

Indications

• Administer magnesium sulfate immediately to all patients with severe preeclampsia or those with proteinuria plus severe hypertension or any neurological symptoms 1, 2

Dosing Protocol (FDA-Approved)

• Loading dose: 4-5 g IV over 5 minutes (diluted in 250 mL of 5% dextrose or 0.9% normal saline) 1, 4
• Maintenance: 1-2 g/hour continuous IV infusion 1, 4
• Alternative regimen: Initial IV dose of 4-5 g, then 4-5 g IM into alternate buttocks every 4 hours as needed 4
• Target serum magnesium level: 6 mg/100 mL for optimal seizure control 4
• Maximum total daily dose: 30-40 g in 24 hours 4

Critical Warning: Continuous maternal administration beyond 5-7 days can cause fetal abnormalities 4

Comprehensive Laboratory and Monitoring Protocol

Initial Laboratory Workup

• Complete blood count with focus on hemoglobin and platelet count 1, 2
• Comprehensive metabolic panel: liver transaminases (AST/ALT), creatinine, uric acid 3, 1, 2
• Spot urine protein/creatinine ratio 1, 2

Ongoing Maternal Monitoring

• Obtain laboratory tests at least twice weekly (or more frequently if clinical deterioration occurs) 3, 1
• Monitor blood pressure continuously or every 4 hours while awake 3, 2
• Perform clinical assessments including deep tendon reflexes and clonus evaluation 3, 2
• Pulse oximetry monitoring 2

Fetal Surveillance

• Initiate serial ultrasound assessments for fetal biometry, amniotic fluid volume, and umbilical artery Doppler to monitor for intrauterine growth restriction 3, 2
• Perform electronic fetal heart rate monitoring to assess fetal well-being 3, 2

Delivery Timing: Gestational Age-Based Algorithm

≥37 Weeks' Gestation

• Deliver immediately after maternal stabilization regardless of severity or laboratory values 1, 2

34-37 Weeks' Gestation

• Without severe features: expectant management with close monitoring is appropriate 1, 2
• With severe features: deliver after maternal stabilization 1, 2

<34 Weeks' Gestation

• Administer antenatal corticosteroids to promote fetal lung maturity 1
• Consider expectant management in select patients with severe preeclampsia between 24-34 weeks in appropriate hospital settings 1
• Expectant treatment before 24 weeks is associated with high maternal morbidity with limited perinatal benefit 1

Absolute Indications for Immediate Delivery (Any Gestational Age)

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

Maternal Indications

• Inability to control BP despite ≥3 classes of antihypertensives in appropriate doses 1
• Repeated episodes of severe hypertension despite treatment 3, 1
• Progressive thrombocytopenia (declining platelet counts on serial measurements) 3, 1
• Progressively abnormal (worsening trends, not static elevations) liver or renal function tests 3, 1
• Pulmonary edema 3, 1
• Maternal oxygen saturation deterioration (<90%) 1
• Severe intractable headache, repeated visual scotomata, or eclamptic seizures 3, 1
• Placental abruption 1

Fetal Indications

• Non-reassuring fetal status on continuous monitoring 3, 1

Critical Pitfall: Do not use serum uric acid level or degree of proteinuria as indications for delivery 3, 1, 2

HELLP Syndrome: Special Considerations

Definition and Recognition

• HELLP syndrome is defined by hemolysis, elevated liver enzymes (AST/ALT ≥2× upper limit of normal), and low platelets 1
• HELLP is part of the preeclampsia spectrum, not a separate disorder, and should be managed as severe preeclampsia 1
• Maternal mortality rate is 3.4% in HELLP syndrome 1
• Epigastric or right upper quadrant pain is a hallmark symptom 1

Management Specifics

• Monitor glucose intraoperatively as severe hypoglycemia can occur 1
• For pulmonary edema: IV nitroglycerin (glycerol trinitrate) starting at 5 mcg/min, gradually increased every 3-5 minutes to maximum 100 mcg/min 1
• Plasma volume expansion is NOT recommended routinely for pulmonary edema 1, 2

Postpartum Management

Immediate Postpartum Period

• Monitor BP and clinical condition at least every 4 hours while awake 1
• Continue antihypertensives administered antenatally 1
• Avoid NSAIDs for postpartum analgesia unless other analgesics are not working, especially if renal disease or placental abruption are present 1
• Monitor as inpatient or closely at home for 72 hours postpartum, as preeclampsia can worsen or initially present after delivery 1

Long-Term Follow-Up

• Review all women at 3 months postpartum to ensure BP, urinalysis, and laboratory abnormalities have normalized 1
• Initiate appropriate referral for further investigations if proteinuria or hypertension persists 1
• Women with preeclampsia have significant long-term cardiovascular risks requiring annual medical review life-long 1

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 3
• Coordinate care with maternal-fetal medicine specialists, neonatology, and anesthesiology teams 3

Critical Pitfalls to Avoid

• Do not underestimate disease severity based on "mild" classification—all preeclampsia can rapidly progress to life-threatening emergencies 1, 2
• Do not delay delivery at ≥37 weeks based on non-reactive NST—delivery is indicated regardless of fetal testing results 1
• Do not reduce antihypertensives if diastolic BP falls <80 mmHg 1
• Do not use low molecular weight heparin for prevention, as it is not indicated even with prior early-onset preeclampsia 3