What is the treatment for preeclampsia?

Treatment of Preeclampsia

Delivery is the only definitive treatment for preeclampsia, with timing determined by gestational age and disease severity, while medical management with antihypertensives and magnesium sulfate serves to stabilize the mother until delivery can be safely accomplished. 1, 2

Immediate Management Priorities

Blood Pressure Control

Severe hypertension (≥160/110 mmHg) requires urgent treatment within minutes to prevent maternal stroke and must be managed in a monitored setting. 1, 2

First-line options for acute severe hypertension:

• Oral nifedipine: 10 mg, repeat every 20 minutes to maximum 30 mg 1, 2
• IV labetalol: 20 mg bolus, then 40 mg after 10 minutes if needed, followed by 80 mg every 10 minutes to maximum 220 mg 3, 1, 2
• IV hydralazine: 5 mg bolus, then 10 mg every 20-30 minutes to maximum 25 mg 3

For non-severe hypertension (≥140/90 mmHg), initiate oral antihypertensives targeting diastolic BP of 85 mmHg and systolic BP between 110-140 mmHg. 1, 2

Critical caveat: Avoid combining IV magnesium with calcium channel blockers due to risk of myocardial depression. 1 Avoid sublingual nifedipine due to risk of precipitous blood pressure drops. 1

Seizure Prophylaxis with Magnesium Sulfate

All women with preeclampsia and severe hypertension or neurological symptoms must receive magnesium sulfate for convulsion prophylaxis. 1, 2

Magnesium sulfate dosing regimen:

• Loading dose: 4 g IV or 10 g IM 2
• Maintenance: 5 g IM every 4 hours OR 1 g/hour IV infusion 2
• Continue for 24 hours postpartum 1, 2
• Effective anticonvulsant serum levels: 2.5-7.5 mEq/L 4

Monitor for magnesium toxicity: Deep tendon reflexes disappear at plasma levels approaching 10 mEq/L, respiratory paralysis may occur at this level, and heart block can develop. 4 Have IV calcium available as an antidote. 3

Fluid Management

Strictly limit total fluid intake to 60-80 mL/hour to prevent pulmonary edema. 1, 2 Aim for euvolemia while avoiding "running dry" as this increases acute kidney injury risk. 1 Diuretics are contraindicated in preeclampsia as they further reduce plasma volume. 1

Hospitalization and Monitoring

All women with preeclampsia should be hospitalized initially to confirm diagnosis, assess severity, and monitor progression. 1, 2

Maternal monitoring protocol:

• Blood pressure every 4 hours (more frequently if severe) 1, 2
• Clinical assessment for clonus and neurological symptoms 1
• Blood tests at least twice weekly: hemoglobin, platelet count, liver enzymes, renal function including uric acid 1

Fetal monitoring:

• Initial assessment to confirm fetal well-being 1, 2
• Serial ultrasound surveillance: fetal biometry, amniotic fluid assessment, umbilical artery Doppler 1, 2

Timing of Delivery

Delivery timing is based on gestational age and presence of severe features:

Deliver Immediately at Any Gestational Age if:

• Repeated episodes of severe hypertension despite treatment with 3 classes of antihypertensives 1, 2
• Placental abruption 1
• Non-reassuring fetal status 1, 2
• Eclampsia (seizures) 2
• Pulmonary edema 2
• Progressive thrombocytopenia 2
• Progressively abnormal renal or liver enzyme tests 2

Gestational Age-Based Delivery Guidelines:

• ≥37 weeks: Deliver all women with preeclampsia 3, 2
• ≥34 weeks with severe features: Deliver 2, 5
• <34 weeks: Administer corticosteroids for 48 hours to accelerate fetal lung maturation, then consider expectant management only in highly selected stable patients 1, 6
• <24 weeks: Discuss termination of pregnancy due to high maternal morbidity with limited perinatal benefit 5, 6

Postpartum Management

Continue close monitoring for at least 3 days postpartum as eclampsia can still develop. 1, 2 Monitor BP at least every 4-6 hours while awake. 1, 2

Continue antihypertensives and taper slowly after days 3-6 postpartum. 1, 2 Women still requiring antihypertensives at discharge should be reviewed within 1 week. 2

All women with preeclampsia should be reviewed at 3 months postpartum. 2 By 3 months, blood pressure, urinalysis, and laboratory tests should have normalized; persistent abnormalities require further investigation. 2

Prevention for High-Risk Women

Low-dose aspirin (75-162 mg/day) should be initiated before 16 weeks' gestation (definitely before 20 weeks) for women with strong clinical risk factors. 3, 2 This reduces preeclampsia risk by 24%, preterm birth by 14%, and intrauterine growth restriction by 20%. 7

Supplemental calcium (1.2-2.5 g/day) should be considered if dietary intake is likely low (<600 mg/day). 1, 2

Critical Pitfalls to Avoid

Do not attempt to classify preeclampsia as "mild" versus "severe" clinically—all cases may become emergencies, often rapidly. 2 Neither serum uric acid nor the level of proteinuria should be used as an indication for delivery. 2

ACE inhibitors are absolutely contraindicated during second and third trimesters due to renal dysgenesis. 1

Long-Term Cardiovascular Risk

Women with a history of preeclampsia have increased lifetime risks of cardiovascular disease, stroke, diabetes mellitus, venous thromboembolic disease, and chronic kidney disease. 1, 2, 7 Counsel all affected women about this increased cardiovascular risk and ensure appropriate long-term follow-up. 1