What is the most appropriate management for a patient with a history of 5 pregnancies and 4 previous births, including 3 cesarean sections, presenting with headache, pain, and visual disturbances, and hypertension (elevated blood pressure)?

Management of Preeclampsia with Severe Features at 37 Weeks

This patient requires immediate magnesium sulfate for seizure prophylaxis, with labetalol as the first-line antihypertensive agent. The correct answer is D - magnesium sulfate, though labetalol (B) should be initiated concurrently for blood pressure control.

Clinical Presentation Analysis

This patient presents with the classic triad of preeclampsia with severe features at 37 weeks gestation:

• Neurological symptoms: Headache and visual disturbances indicate severe preeclampsia with imminent risk of eclamptic seizures 1, 2
• Hypertension: BP 140/100 mmHg in a previously normotensive pregnant woman requires immediate treatment 2
• Gestational age: At 37 weeks with severe features, delivery is indicated 1

The presence of headache and visual disturbances specifically mandates magnesium sulfate for convulsion prophylaxis, as these are warning signs of impending eclampsia 1, 2.

Why Magnesium Sulfate is Essential

Women with preeclampsia who have hypertension with neurological signs or symptoms should receive MgSO4 for convulsion prophylaxis 1. This is non-negotiable in this clinical scenario.

Evidence Supporting Magnesium Sulfate:

• Magnesium sulfate is superior to phenytoin for prevention of eclampsia, with zero eclamptic convulsions in the magnesium group versus 10 convulsions in the phenytoin group (P = 0.004) 3
• The MAGPIE trial established magnesium sulfate as the definitive agent for seizure prophylaxis 2
• Seizures usually terminate after the initial loading dose 4

Dosing Protocol:

• Loading dose: 4 g IV over 10-15 minutes, followed immediately by 5 g IM into each buttock 4
• Maintenance: 5 g IM every 4 hours OR 1 g/hour IV infusion 1, 4
• Duration: Continue until delivery and for at least 24 hours postpartum 1, 5

Why Labetalol Should Be Added

While magnesium sulfate prevents seizures, labetalol is the first-line antihypertensive for blood pressure control 1, 2. The patient's BP of 140/100 mmHg requires treatment to prevent progression to severe hypertension (≥160/110 mmHg) 1.

Labetalol Dosing:

• Oral: 200 mg three times daily initially, up to 2400 mg per day 1, 2
• If BP rises to ≥160/110 mmHg: IV labetalol 20 mg bolus, then 40 mg after 10 minutes, then 80 mg every 10 minutes to maximum 220-300 mg 2
• Target BP: Diastolic 85 mmHg, systolic <160 mmHg 1

Why NOT the Other Options

Lisinopril (A) - CONTRAINDICATED:

• ACE inhibitors are absolutely contraindicated in pregnancy due to fetal renal toxicity, oligohydramnios, and fetal death
• This is never appropriate in pregnancy

Losartan (C) - CONTRAINDICATED:

• Angiotensin receptor blockers cause the same fetal complications as ACE inhibitors
• Absolutely contraindicated in pregnancy

Delivery Planning

At 37 weeks with preeclampsia and severe features (neurological symptoms), delivery should be expedited 1. The guidelines are explicit:

• Women with preeclampsia at ≥37 weeks' gestation should be delivered 1
• Abnormal neurological features such as severe intractable headache or repeated visual scotomata are indications for delivery 1

Given this patient's history of 3 prior cesarean sections, delivery planning should account for increased surgical risk, but the presence of severe features necessitates delivery regardless 1.

Critical Monitoring Requirements

During Magnesium Sulfate Administration:

• Clinical monitoring: Respiratory rate, deep tendon reflexes, urine output (serum monitoring not necessary) 5
• BP monitoring: Every 4-6 hours, continuously during magnesium infusion 2
• Neurological assessment: For worsening headache, visual changes, altered mental status 2

Laboratory Monitoring:

• Hemoglobin, platelets, liver transaminases, creatinine, uric acid should be checked twice weekly (or daily if unstable) 1, 2

Common Pitfall to Avoid

Do not delay magnesium sulfate while waiting for laboratory results or attempting to control blood pressure first. The presence of neurological symptoms (headache and visual disturbances) with hypertension is sufficient to diagnose preeclampsia with severe features and mandate immediate magnesium sulfate 1, 2. Eclamptic seizures can occur rapidly, and 25% of eclamptic women are asymptomatic before their first seizure 6.