What is the treatment plan for a pregnant female diagnosed with preeclampsia?

Management of Preeclampsia

Deliver the fetus and placenta at ≥37 weeks' gestation after maternal stabilization with magnesium sulfate and aggressive blood pressure control—this is the only definitive cure for preeclampsia. 1, 2

Immediate Assessment and Diagnosis

Upon diagnosis of preeclampsia (new-onset hypertension ≥140/90 mmHg after 20 weeks with proteinuria or end-organ dysfunction), immediately assess for severe features that mandate urgent intervention: 1, 3

• Severe hypertension: BP ≥160/110 mmHg on two occasions at least 15 minutes apart 1, 3
• Thrombocytopenia: Platelets <100,000/μL 1, 3
• Renal dysfunction: Creatinine >1.1 mg/dL or doubling of baseline 3
• Liver involvement: Transaminases >2× normal, persistent epigastric or right upper quadrant pain 1, 4
• Neurological symptoms: Severe persistent headache, visual scotomata, altered mental status 1, 2
• Pulmonary edema 1, 2

Critical pitfall: Do not rely on blood pressure levels alone to determine severity—serious organ dysfunction can develop at relatively mild blood pressure elevations. 5 All preeclampsia should be treated as potentially severe, as rapid progression to life-threatening complications can occur even with initially mild presentations. 3

Urgent Blood Pressure Management for Severe Hypertension

When BP ≥160/110 mmHg persists for >15 minutes, initiate IV antihypertensive therapy immediately to prevent maternal cerebral hemorrhage. 1, 2, 5 Target systolic BP 110-140 mmHg and diastolic BP 85 mmHg (or at minimum <160/105 mmHg). 1, 2, 5

First-Line IV Antihypertensive Options:

IV Labetalol (preferred): 2, 5, 3

• 20 mg IV bolus initially
• Then 40 mg after 10 minutes
• Then 80 mg every 10 minutes
• Maximum cumulative dose: 220 mg

IV Hydralazine (alternative): 3, 6

• 5-10 mg IV every 20 minutes as needed

Oral Nifedipine (alternative for non-emergent severe hypertension): 1, 2

• Immediate-release formulation acceptable
• Avoid short-acting nifedipine when combined with magnesium sulfate due to risk of uncontrolled hypotension 5

Medications to Absolutely Avoid:

• ACE inhibitors, ARBs, and direct renin inhibitors: Absolutely contraindicated due to severe fetotoxicity causing renal dysgenesis 2, 5
• Diuretics: Contraindicated as they further reduce plasma volume, which is already contracted in preeclampsia and worsens uteroplacental perfusion 2, 5
• Sodium nitroprusside: Only use as last resort for extreme emergencies due to risk of fetal cyanide poisoning 5

Magnesium Sulfate for Seizure Prophylaxis

Administer magnesium sulfate immediately to all patients with severe preeclampsia or those with any neurological symptoms to prevent eclamptic seizures. 1, 2, 5, 7

Dosing Protocol: 5, 7

Loading dose: 4-5 g IV over 5 minutes (diluted in 250 mL of 5% dextrose or 0.9% normal saline)

Maintenance: 1-2 g/hour continuous IV infusion

Alternative regimen: After IV loading dose, 4-5 g IM into alternate buttocks every 4 hours as needed 7

Target serum magnesium level: 6 mg/100 mL for seizure control 7

Maximum daily dose: 30-40 g per 24 hours 7

Critical warning: Continuous maternal administration beyond 5-7 days can cause fetal abnormalities. 7 In severe renal insufficiency, maximum dosage is 20 g/48 hours with frequent serum magnesium monitoring. 7

Monitoring for Magnesium Toxicity: 5

• Deep tendon reflexes before each dose (loss of reflexes indicates toxicity)
• Respiratory rate (magnesium causes respiratory depression)
• Urine output hourly via Foley catheter (target ≥100 mL/4 hours or >35 mL/hour)

Comprehensive Laboratory and Fetal Surveillance

Initial Laboratory Workup: 2, 3

• Complete blood count with hemoglobin and platelet count
• Comprehensive metabolic panel: liver transaminases (AST/ALT), creatinine, uric acid
• Spot urine protein/creatinine ratio (≥30 mg/mmol confirms significant proteinuria) 1

Repeat labs at least twice weekly, or more frequently if clinical deterioration occurs. 2, 5

Fetal Surveillance: 2, 5

• Ultrasound at diagnosis: fetal biometry, amniotic fluid volume, umbilical artery Doppler
• Repeat ultrasound every 2 weeks if initial assessment normal, more frequently if fetal growth restriction present
• Continuous electronic fetal heart rate monitoring

Delivery Timing: Gestational Age-Based Algorithm

≥37 Weeks' Gestation: 1, 2, 3

Deliver immediately after maternal stabilization with magnesium sulfate and blood pressure control. Induction of labor is associated with improved maternal outcomes. 5

34-37 Weeks' Gestation: 1, 5, 4

• Without severe features: Expectant management with close monitoring is appropriate
• With severe features: Deliver after maternal stabilization

<34 Weeks' Gestation: 5, 4

• Conservative expectant management at a center with Maternal-Fetal Medicine expertise if maternal and fetal status stable
• Administer corticosteroids for 48 hours to accelerate fetal lung maturation 1, 4

<24 Weeks' Gestation: 5

Expectant management is associated with high maternal morbidity with limited perinatal benefit—counsel regarding pregnancy termination.

Absolute Indications for Immediate Delivery (Any Gestational Age)

Deliver immediately regardless of gestational age if any of the following develop: 1, 2, 5, 3

• Inability to control BP despite ≥3 classes of antihypertensives in appropriate doses
• Progressive thrombocytopenia
• Progressively abnormal liver or renal function tests
• Pulmonary edema
• Severe intractable headache, repeated visual scotomata, or eclamptic seizures
• Non-reassuring fetal status on continuous monitoring
• Placental abruption
• Maternal oxygen saturation deterioration (<90-95%)

Management of Specific Complications

HELLP Syndrome: 5, 3

Defined by hemolysis, elevated liver enzymes (>2× normal), and low platelets (<100,000/μL). Maternal mortality rate is 3.4%. 5 Epigastric or right upper quadrant pain is a hallmark symptom suggesting hepatic capsule distension. 5, 4 Monitor glucose intraoperatively as severe hypoglycemia can occur. 5

Pulmonary Edema: 5

Drug of choice: IV nitroglycerin (glycerol trinitrate) starting at 5 mcg/min, gradually increased every 3-5 minutes to maximum 100 mcg/min. Plasma volume expansion is NOT recommended routinely. 5, 3

Eclamptic Seizures: 8, 6

All patients with eclampsia should be treated in an intensive care unit when possible. 8 Magnesium sulfate is the drug of first choice. 1, 8 Eclamptic seizures may develop for the first time in the early postpartum period. 1

Postpartum Management

Early Postpartum Period (First 3 Days): 1

• Monitor BP and clinical condition at least every 4 hours while awake
• Continue antihypertensive medications administered antenatally
• Consider treating any hypertension before day 6 postpartum
• Avoid NSAIDs for postpartum analgesia unless other analgesics are not working, especially if renal disease, placental abruption, acute kidney injury, sepsis, or postpartum hemorrhage present 1, 2

Long-Term Follow-Up: 1

Review at 3 months postpartum to ensure BP, urinalysis, and laboratory abnormalities have normalized. If proteinuria or hypertension persists, initiate appropriate referral for further investigations. Women with preeclampsia have significant long-term cardiovascular risks. 1, 4

Prevention Strategies for Future Pregnancies

Low-Dose Aspirin: 1

Women with established strong clinical risk factors (prior preeclampsia, chronic hypertension, pregestational diabetes, BMI >30 kg/m², antiphospholipid syndrome, assisted reproduction) should receive low-dose aspirin 75-162 mg/day, ideally before 16 weeks but definitely before 20 weeks' gestation.

Calcium Supplementation: 1

Women at increased risk should receive supplemental calcium 1.2-2.5 g/day if dietary intake is likely <600 mg/day, in addition to aspirin.

What NOT to Use: 1

Low molecular weight heparin is not indicated to prevent preeclampsia, even with a history of prior early-onset preeclampsia.

Critical Pitfalls to Avoid

• Do not underestimate disease severity based on "mild" classification—all preeclampsia can rapidly progress to life-threatening complications 5, 3
• Do not use serum uric acid level or degree of proteinuria as indications for delivery 1, 5, 3
• Do not delay delivery at ≥37 weeks based on reassuring fetal testing—delivery is indicated regardless 3
• Do not reduce antihypertensives if diastolic BP falls <80 mmHg 5, 3
• Do not attempt conservative management without appropriate intensive maternal and neonatal care capabilities 2