What is the treatment for preeclampsia?

Treatment of Preeclampsia

The definitive treatment for preeclampsia is delivery of the placenta and fetus, with timing based on gestational age and disease severity; before delivery, management focuses on preventing maternal complications through blood pressure control with antihypertensives and seizure prophylaxis with magnesium sulfate. 1, 2

Immediate Stabilization and Management

Blood Pressure Control

For severe hypertension (≥160/110 mmHg), initiate urgent antihypertensive therapy immediately in a monitored setting. 1, 3 The target blood pressure is systolic 110-140 mmHg and diastolic 85 mmHg to prevent maternal cerebral hemorrhage while maintaining uteroplacental perfusion. 1, 2

First-line antihypertensive options include:

• IV labetalol: 20 mg IV bolus, then 40 mg after 10 minutes if needed, followed by 80 mg every 10 minutes to maximum 220 mg 4, 1, 3
• Oral nifedipine: 10 mg, repeat every 20 minutes to maximum 30 mg 1
• IV hydralazine as an alternative 2

For non-severe hypertension (≥140/90 mmHg but <160/110 mmHg), treat with oral antihypertensives targeting diastolic BP of 85 mmHg and systolic BP between 110-140 mmHg. 1, 2

Critical caveat: Avoid sublingual nifedipine due to risk of precipitous blood pressure drops, and do not combine calcium channel blockers with IV magnesium sulfate due to risk of myocardial depression. 1

Seizure Prophylaxis with Magnesium Sulfate

All women with preeclampsia and severe hypertension or neurological symptoms must receive magnesium sulfate for seizure prophylaxis. 4, 1, 3, 5 Magnesium sulfate more than halves the risk of eclampsia (relative risk 0.41) and probably reduces maternal death. 6, 7

Dosing regimen:

• Loading dose: 4-5 g IV over 5 minutes 1, 3
• Maintenance: 1-2 g/hour continuous IV infusion 1, 3
• Duration: Continue until delivery and for 24 hours postpartum 4, 1

Monitoring for magnesium toxicity:

• Assess deep tendon reflexes before each dose 3
• Monitor respiratory rate (toxicity causes respiratory depression) 3
• Hourly urine output via Foley catheter with target ≥100 mL/4 hours 3
• Therapeutic serum levels: 2.5-7.5 mEq/L 5

Fluid Management

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

Maternal and Fetal Monitoring

Maternal Surveillance

Monitor blood pressure every 4 hours (more frequently if severe disease). 1, 2 Obtain laboratory tests at least twice weekly including:

• Complete blood count (hemoglobin, platelets) 1, 3
• Liver enzymes (transaminases) 1, 3
• Renal function (creatinine, uric acid) 1, 3
• Peripheral blood smear if HELLP syndrome suspected 3

Monitor for clinical warning signs including severe headache, visual disturbances, epigastric or right upper quadrant pain, shortness of breath, and decreased urine output. 1, 3

Fetal Surveillance

Initial assessment should confirm fetal well-being with ultrasound evaluation. 1, 2 Serial ultrasound surveillance should include fetal biometry, amniotic fluid assessment, and umbilical artery Doppler. 1, 2 Repeat ultrasound every 2 weeks if initial assessment normal, more frequently if fetal growth restriction present. 3

Timing of Delivery

Delivery is the definitive treatment and timing depends on gestational age and disease severity. 1, 2

Delivery Timing by Gestational Age:

• ≥37 weeks: Deliver after maternal stabilization 1, 3, 2
• 34-37 weeks: Expectant conservative management if maternal and fetal status stable; deliver if any deterioration occurs 3, 2
• <34 weeks: Conservative expectant management at a center with Maternal-Fetal Medicine expertise; administer corticosteroids for 48 hours to accelerate fetal lung maturation 1, 8
• <24 weeks: Expectant management associated with high maternal morbidity with limited perinatal benefit; counsel regarding pregnancy termination 3

Absolute Indications for Immediate Delivery (at any gestational age):

• Inability to control BP despite ≥3 classes of antihypertensives 1, 3, 2
• Progressive thrombocytopenia or progressively abnormal liver/renal function tests 3, 2
• Pulmonary edema 3, 2
• Severe intractable headache, repeated visual scotomata, or convulsions 3, 2
• Non-reassuring fetal status 1, 3, 2
• Placental abruption 1, 3

Postpartum Management

Continue close monitoring for at least 3 days postpartum as eclampsia can still develop. 1, 2 Monitor blood pressure 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; by this time, blood pressure, urinalysis, and laboratory tests should have normalized. 2

Prevention for High-Risk Women

For women at high risk for preeclampsia, prescribe low-dose aspirin (75-162 mg/day) before 16 weeks' gestation (definitely before 20 weeks). 4, 1, 2 This reduces the risk of preeclampsia by 19% and preterm birth by 7%. 6

Consider supplemental calcium (1.2-2.5 g/day) if dietary intake is likely low (<600 mg/day). 1, 2

Critical Pitfalls to Avoid

Do not attempt to diagnose "mild versus severe" preeclampsia clinically—all cases may become emergencies rapidly. 3, 2 Do not use serum uric acid or level of proteinuria as indication for delivery. 3, 2 Do not reduce antihypertensives if diastolic BP falls <80 mmHg. 3

Medications absolutely contraindicated: ACE inhibitors, ARBs, and direct renin inhibitors due to severe fetotoxicity. 1, 3

Long-term Counseling

Women with a history of preeclampsia have increased lifetime risks of cardiovascular disease, stroke, diabetes mellitus, venous thromboembolic disease, and chronic kidney disease. 2, 8 Counsel patients about these risks and ensure appropriate long-term cardiovascular follow-up. 1, 2