What is the difference in management between pre-eclampsia and gestational hypertension (GHTN)?

Pre-eclampsia vs Gestational Hypertension: Key Differences in Management

The critical distinction is that pre-eclampsia is a multi-system endothelial disorder requiring more aggressive monitoring and earlier delivery, while gestational hypertension is isolated blood pressure elevation requiring close surveillance but less urgent intervention. 1

Fundamental Pathophysiologic Differences

Pre-eclampsia represents a systemic endothelial disorder with vasospasm, reduced organ perfusion, and activation of the coagulation cascade caused by placental hypoperfusion and failure of spiral artery remodeling. 1 It manifests as:

• Hypertension (≥140/90 mmHg) PLUS proteinuria (>300 mg/24h) after 20 weeks gestation 2
• Can progress to HELLP syndrome (hemolysis, elevated liver enzymes, low platelets), headache, visual disturbances, pulmonary edema 1
• Represents a "more ominous condition" with significant maternal and fetal risk 1

Gestational hypertension is distinguished by:

• Isolated blood pressure elevation (≥140/90 mmHg) after 20 weeks gestation 1
• Absence of proteinuria - this is the defining difference 1
• May evolve into transient hypertension (if BP normalizes by 12 weeks postpartum) or chronic hypertension (if elevated beyond 12 weeks) 1

Management Approach by Severity

Severe Range Hypertension (≥160/110 mmHg)

Treat immediately regardless of diagnosis - maternal benefits (preventing intracerebral hemorrhage) outweigh potential fetal harm. 1

First-line acute treatment options: 1

• Intravenous labetalol (100 mg twice daily up to 2400 mg/day) 1
• Oral immediate-release nifedipine (if no IV access) 1
• Intravenous hydralazine (though no longer first-line due to increased perinatal adverse effects) 2

Critical timing: Confirm diagnosis within 15 minutes and initiate treatment within 30-60 minutes. 1

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

This is where management diverges significantly:

For Pre-eclampsia:

• Hospitalization is typically required for severe disease 3
• Close maternal and fetal monitoring mandatory 3
• Magnesium sulfate during labor and ≥24 hours postpartum to prevent eclamptic seizures in severe cases 3, 4
• Delivery is the only definitive cure - timing depends on gestational age and disease severity 2
• Expectant management possible only in select cases <32 weeks with severe disease 3
• Steroids between 24-34 weeks for fetal lung maturity 3

For Gestational Hypertension:

• Close monitoring is mandated but treatment of non-severe BP remains controversial 1
• Current US guidelines (ACOG) do NOT recommend treating gestational hypertension at 140/90 mmHg threshold, unlike chronic hypertension 1
• The CHAP trial demonstrated benefit of treating chronic hypertension to <140/90 mmHg, but this evidence has not been extended to gestational hypertension or pre-eclampsia 1
• Antihypertensive treatment prevents BP exacerbation but has NOT been shown to prevent progression to pre-eclampsia or improve perinatal mortality 1

Pharmacologic Treatment Options for Non-Severe Disease

When treatment is indicated:

First-line agents: 1

• Methyldopa (750 mg to 4 g/day in 3-4 divided doses) - best long-term safety record 1
• Labetalol (100 mg twice daily up to 2400 mg/day) - alpha-beta blocker with vasodilation advantage 1
• Nifedipine (extended-release formulation) 2

Absolutely contraindicated: 2

• ACE inhibitors (cause fetal renal dysgenesis) 2
• Angiotensin receptor blockers (severe fetotoxicity) 2

Avoid or use with extreme caution:

• Sublingual or IV nifedipine (risk of excessive rapid BP reduction causing maternal MI or fetal distress) 1
• Diuretics (reduce plasma volume expansion, theoretical concern for promoting pre-eclampsia) 1
• Calcium channel blockers with IV magnesium (risk of severe hypotension and myocardial depression) 1, 4

Monitoring Intensity Differences

Pre-eclampsia requires:

• Daily laboratory monitoring if abnormal: CBC, platelets, creatinine, liver enzymes 4
• Continuous assessment for HELLP syndrome components 4
• Neurological monitoring for cerebral edema signs (altered consciousness, severe headache, visual changes, seizures) 4
• Strict fluid restriction (60-80 mL/hour) if cerebral edema present 4
• BP checks every 4-6 hours minimum for 3 days postpartum 4

Gestational hypertension requires:

• Close monitoring for progression to pre-eclampsia (20-25% of chronic hypertension cases develop superimposed pre-eclampsia) 1
• Regular proteinuria screening
• Fetal surveillance for growth restriction
• Less intensive laboratory monitoring unless progression occurs

Common Pitfalls to Avoid

1. Do not assume gestational hypertension is benign - it mandates close monitoring as it can progress to pre-eclampsia 1

2. Do not aggressively lower normal BP in pre-eclampsia with cerebral edema - elevated BP may be compensatory to maintain cerebral perfusion pressure 4

3. Do not use hydralazine IV as first-line for acute severe hypertension - associated with more perinatal adverse effects 2

4. Do not extrapolate CHAP trial results to gestational hypertension/pre-eclampsia - evidence only supports treating chronic hypertension to <140/90 mmHg 1

5. Do not discharge pre-eclamptic patients without ensuring 24+ hours of magnesium sulfate in severe cases - eclampsia can occur postpartum 4

Long-term Cardiovascular Risk

Both conditions confer increased long-term cardiovascular risk, but pre-eclampsia (especially preterm) carries substantially higher risk for future hypertension, stroke, ischemic heart disease, and cardiomyopathy. 1, 5 All women require cardiovascular risk assessment and lifestyle modifications postpartum, with follow-up at 3 months to ensure normalization of BP and laboratory values. 1, 4