What are the management options for preeclampsia?

Management of Preeclampsia

Delivery is the definitive treatment for preeclampsia, with timing determined by gestational age and disease severity, while immediate stabilization requires magnesium sulfate for seizure prophylaxis and aggressive blood pressure control for severe hypertension (≥160/110 mmHg). 1, 2

Initial Assessment and Hospitalization

• All women with newly diagnosed preeclampsia should be hospitalized initially to confirm diagnosis, assess severity, and monitor disease progression 1
• Measure blood pressure every 4 hours (more frequently if severe features present) 1
• Assess for neurological symptoms including severe headache, visual disturbances, and clonus 1
• Obtain laboratory tests at least twice weekly: complete blood count with platelets, liver enzymes (AST/ALT), serum creatinine, and uric acid 1, 2
• Perform initial fetal assessment with ultrasound including fetal biometry, amniotic fluid volume, and umbilical artery Doppler 1

Blood Pressure Management

Severe Hypertension (≥160/110 mmHg)

Severe hypertension requires urgent treatment within 15 minutes to prevent maternal cerebral hemorrhage while maintaining uteroplacental perfusion. 1, 2

• First-line IV therapy: Labetalol 1, 2

  • Initial dose: 20 mg IV bolus
  • If inadequate response after 10 minutes: 40 mg IV
  • If still inadequate after another 10 minutes: 80 mg IV every 10 minutes
  • Maximum cumulative dose: 220 mg 1, 3

• Alternative: Oral nifedipine (immediate-release) 1

  • 10 mg orally, repeat every 20 minutes if needed
  • Maximum: 30 mg total 1

• Target blood pressure: Systolic 110-140 mmHg and diastolic 85 mmHg (or at minimum <160/105 mmHg) 1, 2

Critical pitfall: Avoid sublingual nifedipine due to risk of precipitous blood pressure drops that can compromise uteroplacental perfusion 1. Never combine IV magnesium sulfate with calcium channel blockers due to risk of myocardial depression 1.

Non-Severe Hypertension (140-159/90-109 mmHg)

• Treat with oral antihypertensives targeting diastolic BP of 85 mmHg and systolic BP 110-140 mmHg 1
• Acceptable agents include labetalol, nifedipine extended-release, or methyldopa 1

Absolute contraindications: ACE inhibitors, ARBs, and direct renin inhibitors are absolutely contraindicated in pregnancy due to severe fetotoxicity and renal dysgenesis 1, 2

Magnesium Sulfate for Seizure Prophylaxis

Administer magnesium sulfate to all women with severe preeclampsia or those with severe hypertension to prevent eclamptic seizures. 1, 2

Dosing Protocol 3

• Loading dose: 4-5 g IV over 5 minutes (diluted in 250 mL of 5% dextrose or 0.9% normal saline) 1, 3
• Maintenance dose: 1-2 g/hour continuous IV infusion 1, 3
• Alternative regimen: After IV loading dose, give 4-5 g IM into each buttock (10 g total), then 4-5 g IM into alternate buttocks every 4 hours as needed 3
• Duration: Continue for 24 hours postpartum 1, 3

Monitoring for Magnesium Toxicity 2

• Check deep tendon reflexes before each dose (loss of reflexes occurs at plasma levels ~10 mEq/L) 3
• Monitor respiratory rate continuously (respiratory paralysis may occur at levels ~10 mEq/L) 3
• Measure urine output hourly via Foley catheter with target ≥100 mL/4 hours or >35 mL/hour 1, 2
• Monitor oxygen saturation continuously (maternal early warning if <95%) 2
• Therapeutic serum magnesium level: 4-7.5 mEq/L 3

Critical warning: Do not administer magnesium sulfate continuously beyond 5-7 days as this can cause fetal abnormalities 3. In severe renal insufficiency, maximum dose is 20 g/48 hours with frequent serum magnesium monitoring 3.

Fluid Management

Strictly limit total fluid intake to 60-80 mL/hour to prevent pulmonary edema. 1

• 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
• If pulmonary edema develops, use IV nitroglycerin starting at 5 mcg/min, gradually increased every 3-5 minutes to maximum 100 mcg/min 2

Fetal Monitoring

• Perform continuous fetal heart rate monitoring for severe preeclampsia 2
• Repeat ultrasound every 2 weeks if initial assessment normal, more frequently if fetal growth restriction present 2
• Serial umbilical artery Doppler studies to assess placental function 1

Timing of Delivery

Gestational Age ≥37 Weeks

• Deliver immediately after maternal stabilization 1, 2
• Induction of labor is preferred and associated with improved maternal outcomes 4

Gestational Age 34-37 Weeks

• Deliver at 37 weeks for preeclampsia without severe features 1
• Deliver immediately if severe features develop or maternal/fetal condition deteriorates 1, 4

Gestational Age <34 Weeks

• Administer corticosteroids for fetal lung maturation (48-hour course) 1
• Consider expectant management at a center with Maternal-Fetal Medicine expertise if maternal and fetal status remain stable 2, 4
• Average prolongation with expectant management: 7-10 days 4

Absolute Indications for Immediate Delivery (Regardless of Gestational Age) 1, 2

• Repeated episodes of severe hypertension despite treatment with 3 classes of antihypertensives in appropriate doses
• Progressive thrombocytopenia or progressively abnormal liver/renal function tests
• Pulmonary edema
• Severe intractable headache, repeated visual scotomata, or convulsions (eclampsia)
• Non-reassuring fetal status
• Placental abruption
• Maternal pulse oximetry deterioration

Critical consideration: For gestational age <24 weeks, expectant management is associated with high maternal morbidity with limited perinatal benefit—counsel regarding pregnancy termination 4

Postpartum Management

• Continue close monitoring for at least 72 hours postpartum as eclampsia can still develop 1, 5
• Monitor blood pressure at least every 4 hours while awake 1
• Continue magnesium sulfate for 24 hours postpartum 1
• Continue antihypertensives and taper slowly after days 3-6 postpartum 1
• All laboratory abnormalities and blood pressure should normalize by 3 months postpartum; persistent abnormalities require investigation for secondary causes 6

Prevention for Future Pregnancies

• Low-dose aspirin (75-162 mg/day) initiated before 16 weeks' gestation (ideally before 20 weeks) for women with high-risk factors 7, 1
• High-risk factors include: history of preeclampsia (especially early-onset), chronic hypertension, type 1 or 2 diabetes, renal disease, autoimmune disease, or multifetal gestation 7
• Supplemental calcium (1.2-2.5 g/day) if dietary intake is low (<600 mg/day) 1

Long-Term Counseling

• Women with history of preeclampsia have significantly increased lifetime risk of cardiovascular disease, stroke, and venous thromboembolism 6
• Risk of recurrent preeclampsia in future pregnancies is approximately 15%, with additional 15% risk of gestational hypertension 6
• Recommend regular blood pressure monitoring by primary care physician 6
• Screen for depression, anxiety, and post-traumatic stress disorder after severe preeclampsia 6