What are the current management guidelines for a 26‑year‑old woman at 32 weeks gestation with preeclampsia?

Management of Preeclampsia at 32 Weeks Gestation

At 32 weeks gestation with preeclampsia, your patient requires immediate assessment for severe features, urgent blood pressure control if ≥160/110 mmHg, magnesium sulfate for seizure prophylaxis if severe features are present, and delivery planning after maternal stabilization with corticosteroids for fetal lung maturity. 1

Immediate Assessment and Severity Classification

Determine if severe features are present immediately, as this dictates your entire management pathway. 1, 2

Severe features include:

• Blood pressure ≥160/110 mmHg on two occasions at least 15 minutes apart 1, 2
• Thrombocytopenia with platelets <100,000/μL 1, 2
• Elevated liver enzymes (AST/ALT ≥2x upper limit of normal) 2
• Serum creatinine >1.1 mg/dL or doubling of baseline 1, 2
• Pulmonary edema 1, 2
• New-onset severe headache unresponsive to medication 1, 2
• Visual disturbances (scotomata, cortical blindness) 1, 2
• Right upper quadrant or epigastric pain (suggests hepatic capsule distension or HELLP syndrome) 1, 3

Urgent Blood Pressure Management

If blood pressure is ≥160/110 mmHg persisting for more than 15 minutes, initiate IV antihypertensive therapy immediately to prevent maternal cerebral hemorrhage. 1, 4

First-line IV antihypertensive regimen:

• IV labetalol: 20 mg IV bolus, then 40 mg after 10 minutes, then 80 mg every 10 minutes to maximum cumulative dose of 220 mg 1
• Alternative: IV hydralazine 5-10 mg IV every 20 minutes as needed 1
• Oral alternative: Immediate-release nifedipine (if IV access unavailable) 1

Target blood pressure: Systolic 110-140 mmHg and diastolic 85 mmHg (minimum goal <160/105 mmHg). 1, 4 The goal is to decrease mean arterial pressure by 15-25% to prevent stroke while maintaining uteroplacental perfusion. 1

Critical warning: Avoid short-acting oral nifedipine when combined with magnesium sulfate due to risk of uncontrolled hypotension and fetal compromise. 1 Never combine IV or sublingual nifedipine with magnesium sulfate—this can cause severe myocardial depression. 5, 6

Magnesium Sulfate for Seizure Prophylaxis

Administer magnesium sulfate immediately if any severe features are present (including severe hypertension alone). 1, 2, 5 Magnesium sulfate is the most effective agent for preventing eclamptic seizures, superior to phenytoin and diazepam, and reduces the risk of eclampsia by more than half. 5, 7

Dosing regimen:

• Loading dose: 4-5 g IV over 5 minutes (diluted in 250 mL of 5% dextrose or 0.9% normal saline) 1, 2
• Maintenance: 1-2 g/hour continuous IV infusion 1, 2
• Continue for 24 hours postpartum as eclamptic seizures may develop for the first time in the early postpartum period 1, 2

Clinical monitoring protocol (do NOT routinely check serum magnesium levels):

• Urine output ≥100 mL/4 hours (or ≥30 mL/hour) via Foley catheter 1, 5, 8
• Patellar reflexes present before each dose 1, 8
• Respiratory rate ≥12 breaths/minute 1, 8
• Oxygen saturation >90% 5

Only check serum magnesium levels if: renal impairment (elevated creatinine), urine output <30 mL/hour, loss of patellar reflexes, or respiratory rate <12 breaths/minute. 5, 8 Have IV calcium gluconate immediately available as antidote for magnesium toxicity. 8

Comprehensive Laboratory and Fetal Assessment

Obtain immediately:

• Complete blood count with platelet count (assess for HELLP syndrome) 1, 2
• Comprehensive metabolic panel: AST, ALT, creatinine, uric acid 1, 2
• Spot urine protein/creatinine ratio (≥30 mg/mmol confirms significant proteinuria) 1, 2
• Peripheral blood smear if hemolysis suspected 1

Repeat laboratory tests at least twice weekly or more frequently if clinical deterioration occurs. 1, 2

Fetal assessment:

• Continuous fetal heart rate monitoring 1
• Ultrasound at diagnosis: fetal biometry, amniotic fluid volume, umbilical artery Doppler 1, 2
• Repeat ultrasound every 2 weeks if initial assessment normal, more frequently if fetal growth restriction present 1

Corticosteroids for Fetal Lung Maturity

Administer antenatal corticosteroids immediately without delaying delivery to complete the course. 9, 4 At 32 weeks gestation, corticosteroids provide critical neuroprotection and improve fetal lung maturity. 9

Dosing: Betamethasone or dexamethasone per your institutional protocol (typically betamethasone 12 mg IM every 24 hours for 2 doses). 9

Magnesium sulfate also provides neuroprotection when delivery is anticipated before 32 weeks gestation. 9, 5

Delivery Timing at 32 Weeks Gestation

At 32 weeks with preeclampsia, the decision depends on presence of severe features and maternal/fetal stability. 1, 2

If Severe Features Present:

Deliver after maternal stabilization (blood pressure controlled, magnesium sulfate initiated, corticosteroids administered). 1, 2 Do not delay delivery beyond 24-48 hours even if corticosteroid course incomplete. 4

If No Severe Features:

Conservative expectant management at a center with Maternal-Fetal Medicine expertise is appropriate if both maternal and fetal status remain stable. 1, 2 The average interval from diagnosis to delivery at <32 weeks is 14 days, but some require delivery within 72 hours. 1

Absolute Indications for Immediate Delivery (Regardless of Gestational Age):

• Inability to control blood pressure despite ≥3 classes of antihypertensives in appropriate doses 1, 2
• Progressive thrombocytopenia (declining platelet counts on serial measurements) 1, 2
• Progressively abnormal liver or renal function tests (worsening trends, not static elevations) 1, 2
• Pulmonary edema 1, 2
• Severe intractable headache, repeated visual scotomata, or eclamptic seizures 1, 2
• Non-reassuring fetal status on continuous monitoring 1, 2
• Placental abruption 1
• Maternal oxygen saturation deterioration 1

Critical Monitoring Requirements During Expectant Management

Continuous maternal monitoring:

• Blood pressure monitoring continuously until stable, then at least every 4 hours 1, 2
• Hourly urine output via Foley catheter 1
• Oxygen saturation 1
• Assess for severe headache, visual changes, right upper quadrant pain, shortness of breath 1

HELLP Syndrome Recognition

HELLP syndrome is a severe variant of preeclampsia defined by hemolysis, elevated liver enzymes (AST/ALT ≥2x normal), and low platelets (<100,000/μL). 9, 1 Maternal mortality rate is 3.4%. 1, 2

Hallmark symptom: Epigastric or right upper quadrant pain suggesting hepatic capsule distension. 1, 3

Management: Treat as severe preeclampsia with all the above measures. 9 Platelet transfusion should be considered if platelet count <100,000/μL as this is associated with increased risk of abnormal coagulation and adverse maternal outcomes. 9 Deliver promptly once maternal coagulopathy and severe hypertension have been corrected. 9

Medications to Absolutely Avoid

• ACE inhibitors, ARBs, and direct renin inhibitors are absolutely contraindicated due to severe fetotoxicity 1
• Diuretics are contraindicated as they further reduce plasma volume (already contracted in preeclampsia) 1—Exception: Furosemide may be used for pulmonary edema specifically 9, 10
• Methyldopa should be avoided postpartum due to risk of postnatal depression 9

Postpartum Management

Blood pressure often worsens between days 3-6 postpartum. 2, 11 Monitor blood pressure at least every 4 hours while awake for minimum of 3 days postpartum. 1, 2 Continue magnesium sulfate for 24 hours postpartum. 1, 2 Most women with delayed-onset postpartum preeclampsia present within the first 7-10 days after delivery, most frequently with neurologic symptoms (typically headache). 11