What is the management of preeclampsia?

Management of Preeclampsia

Delivery is the only definitive treatment for preeclampsia, but the timing depends on gestational age, disease severity, and maternal-fetal status—with immediate delivery indicated for severe features at ≥34 weeks or any gestational age if maternal or fetal deterioration occurs. 1, 2

Initial Assessment and Hospitalization

• All women with newly diagnosed preeclampsia require initial hospitalization to confirm diagnosis, assess severity, and establish monitoring protocols 1
• Preeclampsia is diagnosed by new-onset hypertension (≥140/90 mmHg) after 20 weeks of gestation with either proteinuria (≥300 mg/24h or spot protein/creatinine ratio ≥30 mg/mmol) or evidence of end-organ damage 1, 3
• Proteinuria is no longer required for diagnosis if other features of end-organ dysfunction are present (thrombocytopenia, renal insufficiency, liver involvement, neurological symptoms, or fetal growth restriction) 3

Blood Pressure Management

Severe Hypertension (≥160/110 mmHg)

Severe hypertension requires urgent treatment within 15 minutes in a monitored setting to prevent maternal cerebral hemorrhage while maintaining uteroplacental perfusion. 1, 2

First-line IV antihypertensive options: 1, 2

• Labetalol: 20 mg IV bolus, then 40 mg after 10 minutes, followed by 80 mg every 10 minutes to maximum 220 mg
• Nifedipine (oral): 10 mg, repeat every 20 minutes to maximum 30 mg
• Nicardipine (IV): Start at 5 mg/h, increase by 2.5 mg/h every 5-15 minutes to maximum 15 mg/h

Target blood pressure: Systolic 110-140 mmHg and diastolic 85 mmHg (or at minimum <160/105 mmHg) 1, 2

Non-Severe Hypertension (140-159/90-109 mmHg)

• Treat with oral antihypertensives targeting diastolic BP of 85 mmHg and systolic BP between 110-140 mmHg 1
• Acceptable oral agents include methyldopa, labetalol, and long-acting nifedipine 4

Critical Contraindications

• ACE inhibitors and ARBs are absolutely contraindicated during second and third trimesters due to fetal renal dysgenesis 5, 2
• Avoid sublingual nifedipine due to risk of precipitous blood pressure drops causing maternal myocardial infarction or fetal distress 1
• Sodium nitroprusside should only be used as last resort in extreme emergencies due to risk of fetal cyanide poisoning 2
• Do not combine IV magnesium sulfate with calcium channel blockers due to risk of severe hypotension and myocardial depression 1, 4

Magnesium Sulfate for Seizure Prophylaxis

Magnesium sulfate must be administered for seizure prophylaxis in all women with severe preeclampsia or those with neurological symptoms. 1, 2, 6

Dosing Regimens 6

IV Regimen (preferred when infusion pumps available):

• Loading dose: 4-5 g IV over 5 minutes (diluted in 250 mL of 5% dextrose or 0.9% saline)
• Maintenance: 1-2 g/hour continuous IV infusion

Combined IV/IM Regimen (Pritchard):

• Loading dose: 4 g IV over 3-4 minutes PLUS 10 g IM (5 g in each buttock) for total of 14 g
• Maintenance: 5 g IM into alternate buttocks every 4 hours

Duration: Continue for 24 hours after delivery or last seizure, whichever is later 4, 6

Monitoring for Magnesium Toxicity 1, 2, 6

• Assess deep tendon reflexes (patellar) before each dose—loss indicates toxicity
• Monitor respiratory rate continuously—respiratory depression occurs at toxic levels
• Maintain urine output ≥100 mL over 4 hours (or >35 mL/hour via Foley catheter)
• Therapeutic serum magnesium level: 4-7 mEq/L (optimal for seizure control: 6 mg/100 mL) 6
• Have injectable calcium gluconate or calcium chloride immediately available to reverse toxicity 4

Critical Warnings 6

• Do not administer magnesium sulfate continuously beyond 5-7 days as it causes fetal skeletal demineralization, osteopenia, and neonatal fractures
• Maximum total daily dose: 30-40 g in 24 hours 6
• In severe renal insufficiency, maximum dose is 20 g/48 hours with frequent serum level monitoring 6

Fluid Management

Strictly limit total fluid intake to 60-80 mL/hour to prevent pulmonary edema. 1, 2, 4

• Replace insensible losses (30 mL/hour) plus anticipated urinary output (0.5-1 mL/kg/hour) 4
• Preeclamptic women have capillary leak and reduced plasma volume, making them highly susceptible to pulmonary edema with excessive fluids 4
• Diuretics are contraindicated as plasma volume is already reduced 1, 4
• Aim for euvolemia; avoid "running dry" as this increases acute kidney injury risk 1

Maternal Monitoring

Clinical Assessment 1, 2

• Blood pressure every 4 hours (more frequently if severe features present)
• Hourly urine output via Foley catheter with target ≥100 mL/4 hours
• Oxygen saturation on room air (maternal early warning if <95%)
• Assess for severe headache, visual disturbances, epigastric or right upper quadrant pain
• Monitor for clonus, altered mental status, shortness of breath

Laboratory Monitoring 1, 2

At least twice weekly (more frequently with clinical deterioration):

• Complete blood count (hemoglobin, platelet count)
• Liver transaminases (AST, ALT)
• Serum creatinine and uric acid
• Peripheral blood smear if HELLP syndrome suspected

Fetal Monitoring

• Initial ultrasound assessment: fetal biometry, amniotic fluid volume, umbilical artery Doppler 1
• Repeat ultrasound every 2 weeks if initial assessment normal, more frequently if fetal growth restriction present 1, 2
• Continuous or intermittent fetal heart rate monitoring depending on severity 2

Timing of Delivery

Delivery Indications by Gestational Age 1, 2

≥37 weeks: Deliver after maternal stabilization with magnesium sulfate and blood pressure control

34-37 weeks:

• Expectant conservative management appropriate if maternal and fetal status stable
• Deliver if any maternal or fetal deterioration occurs

<34 weeks:

• Conservative expectant management at center with Maternal-Fetal Medicine expertise
• Administer corticosteroids for 48 hours to accelerate fetal lung maturation 5, 1

<24 weeks:

• Expectant management associated with high maternal morbidity with limited perinatal benefit
• Counsel regarding pregnancy termination 2

Absolute Indications for Immediate Delivery (Any Gestational Age) 1, 2, 4

• Inability to control blood pressure despite ≥3 classes of antihypertensives in appropriate doses
• Progressive thrombocytopenia or HELLP syndrome
• Progressively abnormal liver or renal function tests
• Pulmonary edema
• Severe intractable headache, repeated visual scotomata, or eclamptic seizures
• Placental abruption
• Non-reassuring fetal status
• Maternal pulse oximetry deterioration

Mode of Delivery 5, 1

• Vaginal delivery is preferred and associated with improved maternal outcomes
• Cesarean delivery reserved for standard obstetric indications
• Epidural analgesia strongly recommended in absence of thrombocytopenia 3

Special Management Considerations

HELLP Syndrome Recognition 2

• Characterized by hemolysis, elevated liver enzymes (>2× normal), and low platelets (<100,000/μL) 3
• Epigastric or right upper quadrant pain is hallmark symptom suggesting hepatic capsule distension 2
• Maternal mortality rate 3.4% 2
• Monitor glucose intraoperatively as severe hypoglycemia can occur 2

Pulmonary Edema Management 2

• Drug of choice: IV nitroglycerin starting at 5 mcg/min, gradually increased every 3-5 minutes to maximum 100 mcg/min
• Plasma volume expansion not recommended routinely

Postpartum Management

• Continue magnesium sulfate for 24 hours after delivery or last seizure 4, 6
• Close monitoring for at least 3 days postpartum as 25-30% of eclamptic seizures occur postpartum 1, 4
• Monitor blood pressure every 4-6 hours for at least 3 days 4
• Continue antihypertensives; taper slowly only after days 3-6 postpartum unless BP <110/70 mmHg 4
• Avoid NSAIDs in women with preeclampsia/eclampsia, especially with acute kidney injury—use alternative analgesia 4
• Check blood pressure and urine at 6 weeks postpartum 4
• Assess for secondary causes of hypertension in women under 40 with persistent hypertension 4

Prevention Strategies for High-Risk Women

Low-dose aspirin (75-162 mg/day) should be initiated before 16 weeks' gestation (definitely before 20 weeks) for women with strong clinical risk factors. 5, 1

• Evidence shows 15% reduction in preeclampsia incidence and 7% reduction in preterm deliveries 5
• Supplemental calcium (1.2-2.5 g/day) if dietary intake likely low (<600 mg/day) 1

Common Pitfalls to Avoid

• Do not attempt to diagnose "mild versus severe" preeclampsia clinically—all cases may become emergencies rapidly 2
• Do not use serum uric acid or level of proteinuria as sole indication for delivery 2
• Do not reduce antihypertensives if diastolic BP falls <80 mmHg 2
• Do not use hydralazine as first-line agent as it was found inferior to other agents 5

Long-Term Counseling

• Women with preeclampsia have increased lifetime cardiovascular risk and require long-term follow-up 1, 7
• Regular exercise during pregnancy may help reduce likelihood of hypertension 1
• Pregnancy serves as a window for identifying future cardiovascular health risks 7