What is the primary treatment approach for a pregnant woman diagnosed with pre-eclampsia?

Treatment of Pre-eclampsia

Delivery is the only definitive treatment for pre-eclampsia, and should occur at 37 weeks' gestation or immediately if severe features develop, regardless of gestational age. 1, 2

Initial Management and Hospitalization

• All women with newly diagnosed pre-eclampsia require immediate hospitalization to confirm diagnosis, assess severity, and establish baseline maternal and fetal status 2, 3
• Monitor blood pressure every 4 hours (more frequently if severe hypertension present) 1, 2
• Obtain baseline laboratory tests at least twice weekly: complete blood count with platelets, liver transaminases (AST/ALT), serum creatinine, and uric acid 1, 2
• Perform initial fetal assessment with ultrasound for biometry, amniotic fluid volume, and umbilical artery Doppler 1, 2
• Assess for neurological symptoms including clonus, severe headache, and visual disturbances 2

Blood Pressure Management

Severe Hypertension (≥160/110 mmHg)

Severe hypertension requires urgent treatment within 15 minutes in a monitored setting to prevent maternal stroke. 2, 4

• First-line: Oral nifedipine 10 mg, repeat every 20 minutes to maximum 30 mg 2, 5
• Alternative: IV labetalol 20 mg bolus, then 40 mg after 10 minutes if needed, followed by 80 mg every 10 minutes to maximum 220 mg 2
• Alternative: IV hydralazine (though associated with more perinatal adverse effects) 1, 5, 6
• Target systolic BP 110-140 mmHg and diastolic BP 85 mmHg 2, 4

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

• Initiate oral antihypertensive therapy with labetalol, nifedipine, or methyldopa 1, 5
• Target diastolic BP 85 mmHg and systolic BP 110-140 mmHg 2, 3

Critical Contraindications

• ACE inhibitors, ARBs, and direct renin inhibitors are absolutely contraindicated due to severe fetotoxicity causing renal dysgenesis 1, 2, 4
• Diuretics are contraindicated as they further reduce plasma volume, which is already compromised in pre-eclampsia and worsens uteroplacental perfusion 1, 2, 4
• Avoid sublingual nifedipine due to risk of precipitous blood pressure drops 1

Magnesium Sulfate for Seizure Prophylaxis

Magnesium sulfate is the drug of choice for preventing eclamptic seizures and must be administered to all women with severe hypertension or neurological symptoms. 1, 2, 7

• Loading dose: 4-5 g IV over 20 minutes OR 10 g IM (5 g in each buttock) 8, 6
• Maintenance: 1-2 g/hour by continuous IV infusion OR 4-5 g IM into alternate buttocks every 4 hours 8, 6
• Continue for 24 hours postpartum 2, 8
• Monitor patellar reflexes and respiratory function; discontinue if reflexes absent or respirations <12/minute 8
• Target serum magnesium level 6 mg/100 mL for seizure control 8
• Do not exceed 30-40 g total daily dose (20 g/48 hours in severe renal insufficiency) 8
• Do not continue beyond 5-7 days as prolonged use causes fetal abnormalities 8

Fluid Management

Strict fluid restriction is essential to prevent pulmonary edema, a life-threatening complication. 2, 3

• Limit total fluid intake to 60-80 mL/hour 2, 3
• Aim for euvolemia; avoid "running dry" as this increases acute kidney injury risk 2
• Diuretics should not be used unless pulmonary edema develops 1

Mandatory Immediate Delivery Indications

Deliver immediately if ANY of the following develop, regardless of gestational age: 1, 2, 4

• Repeated episodes of severe hypertension despite treatment with 3 classes of antihypertensives 1, 2
• Progressive thrombocytopenia 1
• Progressively abnormal liver or renal function tests 1, 2
• Pulmonary edema 1, 2
• Severe intractable headache, repeated visual scotomata, or eclamptic seizures 1, 2
• Non-reassuring fetal status 1, 2
• Placental abruption 2

Timing of Delivery by Gestational Age

• Deliver at 37 weeks and 0 days gestation even without severe features 1
• For gestations <34 weeks requiring delivery, administer corticosteroids for 48 hours to accelerate fetal lung maturation 1, 2
• For gestations <24 weeks, transfer to tertiary perinatal center with maternal-fetal medicine expertise if expectant management attempted 3

Postpartum Management

Women remain at high risk for complications for at least 3 days postpartum, as eclampsia can develop for the first time during this period. 1, 2

• Monitor BP at least every 4 hours while awake 1, 2
• Continue antihypertensive medications; taper slowly after days 3-6 postpartum, never cease abruptly 1, 2
• Avoid NSAIDs for postpartum analgesia unless other analgesics fail, especially if renal disease, placental abruption, acute kidney injury, sepsis, or postpartum hemorrhage present 1
• Review at 3 months postpartum to ensure BP, urinalysis, and laboratory abnormalities have normalized 1

Prevention Strategies for High-Risk Women

Low-dose aspirin is the most effective preventive intervention and should be started before 16 weeks' gestation (definitely before 20 weeks). 1

Aspirin Prophylaxis

• Dose: 75-162 mg daily (preferably 150 mg at night) 1
• Indications: Previous pre-eclampsia, chronic hypertension, pregestational diabetes, BMI >30 kg/m², antiphospholipid syndrome, multiple pregnancy, assisted reproduction, underlying renal disease 1
• Continue until 36 weeks' gestation or when pre-eclampsia develops 1

Calcium Supplementation

• Dose: 1.2-2.5 g elemental calcium daily 1
• Indicated if dietary calcium intake <600-800 mg/day 1
• When intake cannot be assessed, reasonable to give calcium supplementation 1

Exercise

• Exercise at least 3 days per week for 50 minutes using combination of aerobic exercise, strength, and flexibility training 1
• Associated with reduced gestational hypertension, pre-eclampsia, and less weight gain 1

Not Recommended

• Low molecular weight heparin is NOT indicated for prevention, even with prior early-onset pre-eclampsia 1
• Vitamin C and E supplementation not recommended and may worsen outcomes 1

Long-Term Counseling

Women with pre-eclampsia have significantly increased lifetime cardiovascular risk and require ongoing medical surveillance. 1, 3

• Increased risks of stroke, cardiovascular disease, diabetes, venous thromboembolism, and chronic kidney disease 1, 3
• Recommend annual medical review lifelong 1
• Aim to achieve pre-pregnancy weight by 12 months and limit interpregnancy weight gain 1
• Adopt healthy lifestyle including exercise, healthy eating, and ideal body weight 1

Common Pitfalls to Avoid

• Do not use blood pressure level alone to determine disease severity—serious organ dysfunction can develop at relatively mild BP elevations 4
• Do not use serum uric acid level or degree of proteinuria as indications for delivery 4
• Do not combine IV magnesium with calcium channel blockers due to myocardial depression risk 1, 2
• Do not use sublingual or rapid IV calcium channel blockers to prevent excessive BP reduction leading to myocardial infarction or fetal distress 1
• Pre-eclampsia rarely occurs before 20 weeks except with trophoblastic disease (hydatidiform mole)—consider alternative diagnoses 4