What is the recommended management for a pregnant woman with pre-eclampsia (high blood pressure during pregnancy)?

Management of Preeclampsia

For a pregnant woman diagnosed with preeclampsia, immediate management depends critically on gestational age and disease severity: administer magnesium sulfate for seizure prophylaxis if severe features are present, aggressively control blood pressure to target systolic 110-140 mmHg and diastolic 85 mmHg, and deliver at ≥37 weeks after maternal stabilization—while earlier gestational ages require individualized timing based on maternal-fetal status at a specialized center. 1, 2

Initial Assessment and Risk Stratification

Diagnosis Confirmation

• Preeclampsia is defined as new-onset hypertension (≥140/90 mmHg) after 20 weeks gestation with either proteinuria (≥300 mg/24 hours or protein/creatinine ratio ≥30 mg/mmol) OR evidence of end-organ damage. 1
• All cases should be considered potentially severe as they can rapidly progress to life-threatening emergencies within hours. 1, 2
• Critical pitfall: Do not rely on blood pressure alone to determine severity—serious organ dysfunction can develop at relatively mild BP elevations. 3, 2

Severe Features Assessment

Severe preeclampsia is present with any of the following: 1, 2

• Severe hypertension: BP ≥160/110 mmHg
• Neurological symptoms: severe intractable headache, visual scotomata, altered mental status
• Epigastric or right upper quadrant pain (suggests hepatic capsule distension or HELLP syndrome)
• Renal dysfunction: creatinine >1.1 mg/dL or oliguria <100 mL/4 hours
• Thrombocytopenia: platelets <100,000/μL
• Elevated liver enzymes: AST/ALT >2x upper limit of normal
• Pulmonary edema

Immediate Management Protocol

Blood Pressure Control

Severe hypertension (≥160/110 mmHg persisting >15 minutes) requires urgent treatment within minutes to prevent maternal stroke. 1, 2

First-line antihypertensive options: 1, 2

• IV labetalol: 20 mg IV bolus, then 40 mg after 10 minutes, then 80 mg every 10 minutes to maximum 220 mg
• IV nicardipine or IV hydralazine as alternatives
• Oral nifedipine is preferred for non-urgent blood pressure control 4

Target blood pressure: systolic 110-140 mmHg, diastolic 85 mmHg. 1, 2 The goal is to decrease mean BP by 15-25% to prevent cerebral hemorrhage while maintaining uteroplacental perfusion. 2

Critical pitfall: Avoid short-acting oral nifedipine when combined with magnesium sulfate due to risk of uncontrolled hypotension and fetal compromise. 2

Seizure Prophylaxis with Magnesium Sulfate

Magnesium sulfate must be administered immediately for: 1, 4, 2

• All women with severe preeclampsia
• Any woman with neurological symptoms (severe headache, visual changes)
• Severe hypertension (≥160/110 mmHg)

Dosing regimen: 4, 2

• Loading dose: 4-5 g IV over 5 minutes
• Maintenance: 1-2 g/hour continuous IV infusion
• Continue for 24 hours postpartum (eclampsia can occur postpartum with 0.6% recurrence rate with magnesium vs 2% without) 4

Monitoring for magnesium toxicity: 2

• Assess deep tendon reflexes before each dose
• Monitor respiratory rate (toxicity causes respiratory depression)
• Hourly urine output via Foley catheter with target ≥100 mL/4 hours

Comprehensive Laboratory Assessment

Obtain immediately: 1, 2

• Complete blood count (hemoglobin, platelets—thrombocytopenia <100,000/μL suggests HELLP)
• Comprehensive metabolic panel (AST/ALT, creatinine, uric acid)
• Spot urine protein/creatinine ratio if not already confirmed

Repeat at least twice weekly or more frequently with clinical deterioration. 2

Fluid Management

Total fluid intake must be strictly limited to 60-80 mL/hour to prevent pulmonary edema. 1, 4 Target urine output 0.5-1 mL/kg/hour or >35 mL/hour. 4, 2

For pulmonary edema: IV nitroglycerin starting at 5 mcg/min, gradually increased every 3-5 minutes to maximum 100 mcg/min. 2 Plasma volume expansion is not recommended. 2

Maternal and Fetal Monitoring

Maternal Monitoring Requirements

Continuous or every 4-hour monitoring includes: 1, 4, 2

• Blood pressure measurements
• Oxygen saturation (maternal early warning if <95%)
• Neurological assessment (agitation, confusion, unresponsiveness)
• Symptoms: non-remitting headache, visual disturbances, epigastric/RUQ pain, shortness of breath

Fetal Assessment

Electronic fetal heart rate monitoring should be performed continuously or at regular intervals to assess fetal well-being. 4, 2

Ultrasound assessment at diagnosis: 2

• Fetal biometry, amniotic fluid volume, umbilical artery Doppler
• Repeat every 2 weeks if initial assessment normal, more frequently if fetal growth restriction present

Delivery Timing: The Definitive Treatment

Delivery is the definitive treatment for preeclampsia. 1, 5, 6 The American College of Obstetricians and Gynecologists provides clear gestational age-based guidelines:

≥37 Weeks Gestation

Immediate delivery is indicated after maternal stabilization with magnesium sulfate and blood pressure control. 1, 2 Induction of labor is associated with improved maternal outcomes. 2

34-37 Weeks Gestation

Expectant conservative management is appropriate if maternal and fetal status remain stable. 3, 2 Deliver if any maternal or fetal deterioration occurs. 2

<34 Weeks Gestation

Conservative expectant management at a center with Maternal-Fetal Medicine expertise. 3, 2 The average interval from diagnosis to delivery at <32 weeks is 14 days, though some require delivery within 72 hours. 2

Administer corticosteroids between 24-34 weeks gestation to reduce neonatal mortality and morbidity. 5

Absolute Indications for Immediate Delivery (Regardless of Gestational Age)

Deliver immediately after maternal stabilization if any of the following develop: 3, 2

• Inability to control BP despite ≥3 classes of antihypertensives in appropriate doses
• Maternal pulse oximetry <90% or pulmonary edema
• Progressive deterioration in liver function, creatinine, hemolysis, or platelet count
• Ongoing neurological features: severe intractable headache, repeated visual scotomata, or eclampsia
• Placental abruption
• Non-reassuring fetal status (reversed end-diastolic flow on umbilical artery Doppler, non-reassuring cardiotocograph, or stillbirth)

Critical pitfall: Do not use serum uric acid or level of proteinuria as indication for delivery. 3, 2

HELLP Syndrome Recognition

HELLP syndrome (Hemolysis, Elevated Liver enzymes, Low Platelets) carries 3.4% maternal mortality. 4, 2

Hallmark symptom: Epigastric or right upper quadrant pain. 4, 2 This suggests hepatic capsule distension and requires immediate attention.

Monitor glucose intraoperatively as severe hypoglycemia can occur. 2

Postpartum Management

Close monitoring must continue for at least 3 days postpartum as eclampsia can still develop. 1, 4

Postpartum protocol: 4

• Continue magnesium sulfate for 24 hours postpartum
• Monitor BP at least every 4-6 hours for at least 3 days
• Repeat laboratory tests (hemoglobin, platelets, creatinine, liver enzymes) the day after delivery and every other day until stable
• Avoid NSAIDs for postpartum analgesia, especially with renal dysfunction, as they worsen hypertension and renal function 4

Prevention Strategies

Low-Dose Aspirin for High-Risk Women

The USPSTF recommends low-dose aspirin (81 mg/day) as preventive medication after 12 weeks gestation in women at high risk for preeclampsia. 3 The British Medical Journal suggests initiating before 16 weeks gestation at 75-162 mg/day. 1

High-risk factors include: 3

• History of eclampsia or preeclampsia (particularly early-onset)
• Previous adverse pregnancy outcome
• Maternal comorbid conditions (type 1 or 2 diabetes, gestational diabetes, chronic hypertension, renal disease, autoimmune diseases)
• Multifetal gestation
• Nulliparity, obesity, African American race, advanced maternal age

Ineffective Interventions

The following have been shown ineffective and are not recommended: 7

• Fish oil supplementation
• Calcium supplementation
• Vitamin C and E supplementation
• Prophylactic antihypertensives in women without hypertension

Medications to Absolutely Avoid

ACE inhibitors, ARBs, and direct renin inhibitors are absolutely contraindicated due to severe fetotoxicity. 2

Diuretics are contraindicated as they further reduce plasma volume. 2

Sodium nitroprusside should only be used as last resort for extreme emergencies due to risk of fetal cyanide poisoning. 2

Long-Term Implications

Women with a history of preeclampsia have significantly increased lifetime cardiovascular risk. 1 They require long-term cardiovascular risk assessment and management in the postpartum period and beyond. 7, 8

Screening Recommendations

All pregnant women should undergo blood pressure screening at every prenatal visit throughout pregnancy. 3, 1, 9 The USPSTF gives this a Grade B recommendation with moderate certainty of substantial net benefit. 3, 9

Proper technique: 3

• Patient relaxed for 5 minutes, sitting position, legs uncrossed, back supported
• Arm at level of right atrium
• Use large cuff if upper arm circumference ≥33 cm
• Avoid measuring in left lateral position (falsely lowers readings)