What is the management approach for a pregnant woman diagnosed with preeclampsia?

Management of Preeclampsia

Deliver all women with preeclampsia at ≥37 weeks' gestation regardless of severity, and immediately stabilize severe hypertension (≥160/110 mmHg) with antihypertensive therapy plus magnesium sulfate for seizure prophylaxis when severe features are present. 1, 2

Initial Assessment and Diagnosis

• Confirm preeclampsia by documenting blood pressure ≥140/90 mmHg on repeat measurements after 20 weeks' gestation 2
• Proteinuria is no longer mandatory for diagnosis, but when present is confirmed by spot urine protein/creatinine ratio ≥30 mg/mmol (0.3 mg/mg), ≥300 mg/24 hours, or ≥1+ on dipstick 1, 2
• Treat all cases as potentially severe—rapid progression to life-threatening complications can occur even with initially mild presentations 2, 3
• Blood pressure level alone does not determine disease severity; serious organ dysfunction can develop at relatively mild hypertension levels 2, 3

Severity Classification: Identify Severe Features Immediately

Severe features requiring urgent intervention include: 2

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

Immediate Stabilization for Severe Hypertension

When BP ≥160/110 mmHg persists for >15 minutes, initiate urgent antihypertensive therapy immediately to prevent maternal cerebral hemorrhage. 2, 4

First-Line Antihypertensive Options:

• IV labetalol: 20 mg IV bolus, then 40 mg after 10 minutes, then 80 mg every 10 minutes (maximum cumulative dose 220 mg) 2
• IV hydralazine: 5-10 mg IV every 20 minutes as needed 2
• Oral nifedipine: Alternative first-line option 4, 3

Blood Pressure Targets:

• Target systolic BP 110-140 mmHg and diastolic BP 85 mmHg (or at minimum <160/105 mmHg) 2, 3
• Do not reduce antihypertensives if diastolic BP falls <80 mmHg 2

Critical Contraindications:

• Never use ACE inhibitors, ARBs, or direct renin inhibitors—these cause severe fetotoxicity and renal dysgenesis 4
• Avoid diuretics routinely as they further reduce plasma volume, which is already contracted in preeclampsia and worsens uteroplacental perfusion 2, 4

Magnesium Sulfate for Seizure Prophylaxis

Administer magnesium sulfate immediately to all patients with severe preeclampsia or those with proteinuria plus severe hypertension or any neurological symptoms. 2, 3, 5

Dosing Protocol: 6

• 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: Simultaneously give IM doses of up to 10 g (5 g in each buttock), then 4-5 g IM into alternate buttocks every 4 hours as needed

Monitoring and Safety:

• Effective anticonvulsant serum levels range from 2.5 to 7.5 mEq/L (optimal 6 mg/100 mL for seizure control) 6
• Deep tendon reflexes disappear as plasma level approaches 10 mEq/L; respiratory paralysis may occur at this level 6
• Continue therapy until paroxysms cease; total daily dose should not exceed 30-40 g 6
• Do not use magnesium sulfate continuously beyond 5-7 days as it can cause fetal abnormalities 6
• In severe renal insufficiency, maximum dosage is 20 g/48 hours with frequent serum magnesium monitoring 6

Comprehensive Laboratory and Fetal Assessment

Initial Laboratory Workup: 2, 3

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

Ongoing Monitoring:

• Repeat laboratory tests at least twice weekly or more frequently if clinical deterioration occurs 2, 4
• Monitor blood pressure continuously or every 4 hours while awake 4, 3
• Assess deep tendon reflexes and clonus 4, 3

Fetal Surveillance: 2, 3

• Serial ultrasound for fetal biometry, amniotic fluid volume, and umbilical artery Doppler
• Electronic fetal heart rate monitoring to assess fetal well-being

Delivery Timing: Gestational Age-Based Algorithm

At ≥37 Weeks' Gestation:

Deliver immediately after maternal stabilization—all women with preeclampsia should undergo induction of labor for delivery. 1, 2, 7

At 34-37 Weeks' Gestation:

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

At <34 Weeks' Gestation:

• Expectant management is possible in select women with severe preeclampsia between 24-32 weeks in a suitable tertiary care hospital 7, 8, 5
• Administer corticosteroids for fetal lung maturity if delivery is likely within 7 days 1
• Average pregnancy prolongation with expectant management is 7-13 days 7, 8

Absolute Indications for Immediate Delivery (Any Gestational Age)

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

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

HELLP Syndrome: Special Considerations

• HELLP syndrome (hemolysis, elevated liver enzymes, low platelets) is part of the preeclampsia spectrum and should be managed as severe preeclampsia 2, 9
• Maternal mortality rate is 3.4% in HELLP syndrome 2
• Epigastric or right upper quadrant pain is a hallmark symptom 2
• Monitor glucose intraoperatively as severe hypoglycemia can occur 2

Management of Pulmonary Edema

• Drug of choice is IV nitroglycerin (glycerol trinitrate) starting at 5 mcg/min, gradually increased every 3-5 minutes to maximum 100 mcg/min 2
• Plasma volume expansion is NOT recommended routinely 2, 3

Postpartum Management

• Women with preeclampsia remain at high risk for complications for at least 3 days postpartum 1
• Monitor BP and clinical condition at least every 4 hours while awake 1
• Continue antihypertensives administered antenatally; consider treating any hypertension before day 6 postpartum 1
• Withdraw antihypertensive therapy slowly over days, not abruptly—eclamptic seizures may develop for the first time in the early postpartum period 1
• Avoid NSAIDs for postpartum analgesia unless other analgesics are not working, especially if renal disease, placental abruption, AKI, sepsis, or postpartum hemorrhage are present 1

Follow-Up and Long-Term Considerations

• Review all women at 3 months postpartum to ensure BP, urinalysis, and laboratory abnormalities have normalized 1
• If proteinuria or hypertension persists, initiate appropriate referral for further investigations 1
• Women with preeclampsia have significant long-term cardiovascular risks requiring annual medical review life-long 1
• Recommend achieving prepregnancy weight by 12 months and limiting interpregnancy weight gain through healthy lifestyle 1

Critical Pitfalls to Avoid

• Do not underestimate disease severity based on "mild" classification—all preeclampsia can rapidly progress 2, 3
• Do not use serum uric acid level or degree of proteinuria as indications for delivery 2, 4, 3
• Do not delay delivery at ≥37 weeks based on non-reactive NST—delivery is indicated regardless of fetal testing results 2
• Recognize that preeclampsia rarely occurs before 20 weeks except with trophoblastic disease (hydatidiform mole); consider alternative diagnoses 4