What is the management of preeclampsia?

Management of Preeclampsia

Initial Assessment and Hospitalization

All women with newly diagnosed preeclampsia require immediate hospitalization to confirm diagnosis, assess severity, establish monitoring protocols, and determine whether expectant management or delivery is appropriate. 1, 2

• Diagnose preeclampsia by new-onset hypertension (≥140/90 mmHg) after 20 weeks gestation with either proteinuria (≥300 mg/24h or spot protein/creatinine ratio ≥30 mg/mmol) or evidence of end-organ damage 1, 2
• Assess for severe features: systolic BP ≥160 mmHg or diastolic BP ≥110 mmHg, severe headache, visual disturbances, epigastric/right upper quadrant pain, elevated liver enzymes, thrombocytopenia (platelets <100,000), renal dysfunction (creatinine >1.1 mg/dL), or pulmonary edema 1, 3

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Blood Pressure Management Algorithm

For Severe Hypertension (≥160/110 mmHg)

Initiate urgent IV antihypertensive therapy within 15 minutes when severe hypertension persists for more than 15 minutes to prevent maternal cerebral hemorrhage. 1, 2, 3

First-line options:

• IV labetalol: 20 mg IV bolus, then 40 mg after 10 minutes if needed, followed by 80 mg every 10 minutes to maximum total dose of 220 mg 1, 3, 4
• Oral nifedipine: 10 mg orally, repeat every 20 minutes to maximum 30 mg 1
• IV hydralazine: Alternative option if labetalol/nifedipine unavailable 1

Target blood pressure: Systolic 110-140 mmHg and diastolic 85 mmHg (or at minimum <160/105 mmHg) 1, 2, 3

Critical contraindications:

• ACE inhibitors and ARBs are absolutely contraindicated during second and third trimesters due to fetal renal dysgenesis 1, 2
• Avoid sublingual nifedipine due to risk of precipitous BP drops 1
• Do not combine IV magnesium with calcium channel blockers due to myocardial depression risk 1

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

• Initiate oral antihypertensives (labetalol, nifedipine, or methyldopa) targeting diastolic BP of 85 mmHg and systolic BP 110-140 mmHg 1

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Magnesium Sulfate for Seizure Prophylaxis

Administer magnesium sulfate immediately for all women with severe preeclampsia or those with neurological symptoms (severe headache, visual disturbances) to prevent eclamptic seizures. 1, 2, 3

Dosing regimen (from FDA label):

• Loading dose: 4-5 g IV over 5 minutes (diluted in 250 mL of 5% dextrose or 0.9% saline) 4
• Maintenance dose: 1-2 g/hour continuous IV infusion 1, 2, 4
• Alternative IM regimen: 10 g IM (5 g in each buttock) simultaneously with 4 g IV loading dose, then 4-5 g IM into alternate buttocks every 4 hours 4
• Duration: Continue for 24 hours postpartum or 24 hours after last seizure 5, 2, 4

Monitoring for magnesium toxicity:

• Check deep tendon reflexes before each dose (reflexes disappear at plasma levels ~10 mEq/L) 4
• Monitor respiratory rate (respiratory paralysis may occur at ~10 mEq/L) 3, 4
• Hourly urine output via Foley catheter with target ≥100 mL/4 hours 3
• Therapeutic serum magnesium level: 2.5-7.5 mEq/L (optimal for seizure control is 6 mg/100 mL) 4

Critical warning: Do not use magnesium sulfate continuously beyond 5-7 days as it causes fetal skeletal demineralization, osteopenia, and neonatal fractures 4

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Fluid Management

Strictly limit total fluid intake to 60-80 mL/hour to prevent pulmonary edema, as preeclamptic women have capillary leak and are at high risk for fluid overload. 5, 1, 2

• Replace insensible losses (30 mL/h) plus anticipated urinary losses (0.5-1 mL/kg/hour) 5
• Diuretics are absolutely contraindicated as plasma volume is already reduced in preeclampsia 1, 2
• Avoid "running dry" as this increases acute kidney injury risk 5, 1

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Maternal Monitoring Protocol

Continuous surveillance:

• Blood pressure every 4 hours (more frequently if severe features present) 5, 1
• Assess for severe headache, visual disturbances, epigastric/right upper quadrant pain, shortness of breath 1, 3
• Evaluate for clonus and neurological symptoms 1
• Oxygen saturation monitoring (maternal early warning if <95%) 3

Laboratory monitoring:

• At least twice weekly (or more frequently with clinical deterioration): complete blood count, platelet count, liver transaminases (AST/ALT), creatinine, and uric acid 5, 1, 3
• Repeat labs the day after delivery and then every other day until stable if abnormal before delivery 5

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Fetal Monitoring Protocol

Initial assessment:

• Ultrasound at diagnosis: fetal biometry, amniotic fluid assessment, umbilical artery Doppler 1, 3
• Continuous or intermittent fetal heart rate monitoring depending on severity 3

Ongoing surveillance:

• Repeat ultrasound every 2 weeks if initial assessment normal 3
• More frequent ultrasound if fetal growth restriction present 3
• Non-stress tests or biophysical profiles as clinically indicated 6

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Timing of Delivery Algorithm

≥37 Weeks Gestation

Proceed with delivery (induction of labor preferred over cesarean unless obstetric indications exist). 1, 2, 3

• Induction of labor is associated with improved maternal outcomes 3, 6

34-37 Weeks Gestation

Expectant conservative management is appropriate if maternal and fetal status remain stable. 1, 2, 3

• Deliver if any maternal or fetal deterioration occurs 3
• Administer corticosteroids for fetal lung maturation if not previously given 1, 2

<34 Weeks Gestation

Conservative expectant management at a tertiary center with Maternal-Fetal Medicine expertise is appropriate for carefully selected patients. 1, 3, 7

• Administer corticosteroids for 48 hours to accelerate fetal lung maturation 1, 2
• Approximately two-thirds of patients with severe preeclampsia before 34 weeks are eligible for conservative management 7
• Average pregnancy prolongation with expectant management: 7-10 days 6

<24 Weeks Gestation

Counsel regarding pregnancy termination, as expectant management is associated with high maternal morbidity with limited perinatal benefit. 3, 6

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Absolute Indications for Immediate Delivery (Regardless of Gestational Age)

Deliver immediately after maternal stabilization with magnesium sulfate and blood pressure control if ANY of the following occur:

• Inability to control BP despite ≥3 classes of antihypertensives in appropriate doses 1, 3
• Eclampsia (seizures) or imminent eclampsia (persistent severe neurological symptoms) 3, 6
• Progressive thrombocytopenia or progressively abnormal liver/renal function tests 3, 8
• Pulmonary edema 3, 8
• Severe intractable headache or repeated visual scotomata 3
• Placental abruption 1, 3
• Non-reassuring fetal status 1, 3
• Maternal pulse oximetry deterioration 3
• HELLP syndrome with severe features 3

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Intrapartum Management

• Continue oral antihypertensives at start of labor 5
• Treat severe hypertension urgently with oral nifedipine or IV labetalol/hydralazine if BP rises ≥160/110 mmHg 5
• Maintain fluid restriction at 60-80 mL/hour 5
• Continue magnesium sulfate infusion throughout labor and delivery 5, 4

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Postpartum Management

Close monitoring is essential for at least 3 days postpartum, as 25-30% of eclamptic seizures occur postpartum and preeclampsia may develop de novo in the early postpartum period. 5, 2

Immediate postpartum (Days 0-3):

• Monitor BP at least every 4-6 hours while awake 5, 2
• Continue magnesium sulfate for 24 hours after delivery 5, 2, 4
• Monitor neurological status and general well-being 5
• Repeat labs (hemoglobin, platelets, creatinine, liver transaminases) day after delivery and then every other day until stable if abnormal before delivery 5

Antihypertensive management:

• Restart or continue antihypertensives after delivery 5, 2
• Taper slowly only after days 3-6 postpartum unless BP becomes low (<110/70 mmHg) or woman becomes symptomatic 5, 2

Pain management:

• Avoid NSAIDs if possible, especially with acute kidney injury, as they may worsen hypertension and renal function 5
• Use alternative analgesia (acetaminophen, opioids) as first choice 5

Discharge criteria:

• Most women can be discharged by day 5 postpartum, especially when able to monitor BP at home 5
• Discharge only when BP stable and trending downward 5

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Short-Term Follow-Up (1 Week to 3 Months)

• Review within 1 week if still requiring antihypertensives at hospital discharge 5
• All women must be reviewed at 3 months postpartum by which time BP, urinalysis, and all laboratory tests should have normalized 5
• Further investigation required for persistent abnormalities, including work-up for secondary causes of persistent severe hypertension or underlying renal disease with persistent proteinuria 5
• Screen for depression, anxiety, or posttraumatic stress disorder symptoms 5

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Long-Term Cardiovascular Risk Counseling

Counsel all women that preeclampsia significantly increases lifetime risk of cardiovascular disease, stroke, diabetes mellitus, venous thromboembolism, and chronic kidney disease compared to women with normotensive pregnancies. 5, 1

• Lifelong follow-up required for all women with gestational hypertension or preeclampsia 5
• Encourage lifestyle modifications: regular exercise, healthy diet, weight management, smoking cessation 5

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Prevention for Future Pregnancies

For women at high risk of preeclampsia in future pregnancies, initiate low-dose aspirin (75-162 mg/day) before 16 weeks gestation (ideally before 12 weeks, definitely before 20 weeks). 5, 1, 2

High-risk factors include:

• History of preeclampsia in prior pregnancy
• Chronic hypertension
• Pregestational diabetes
• Renal disease
• Autoimmune disease
• Multiple gestation

Additional prevention:

• Supplemental calcium (1.2-2.5 g/day) if dietary intake likely low (<600 mg/day) 1, 2