Overview
Eclampsia
Quick Reference
Critical Alerts
- Magnesium sulfate is first-line: NOT benzodiazepines or phenytoin
- Delivery is definitive treatment: Do not delay for non-viable fetus
- Can occur postpartum: Up to 6 weeks after delivery
- Fetal monitoring is essential: Fetal distress common during/after seizure
- Control blood pressure: Target SBP <160, DBP <110
- HELLP syndrome coexists in 10-20%: Check LFTs and platelets
Key Diagnostics
| Test | Finding | Significance |
|---|---|---|
| BP | ≥140/90 (often ≥160/110) | Defines hypertensive disease |
| Urine protein | Proteinuria (>00mg/24h or ≥2+ dipstick) | But may be absent in 15% |
| CBC | Thrombocytopenia (<100,000) | HELLP syndrome |
| LFTs | Elevated AST/ALT | HELLP syndrome |
| Creatinine | Elevated | Renal involvement |
| LDH | Elevated (>00 U/L) | Hemolysis in HELLP |
| Uric acid | Elevated | Often elevated in preeclampsia |
Emergency Treatments
| Condition | Treatment | Dose |
|---|---|---|
| Seizure control | Magnesium sulfate | 4-6g IV over 15-20 min, then 1-2g/hr infusion |
| Recurrent seizure on Mg | Additional magnesium bolus | 2g IV over 5 min |
| Refractory seizures | Lorazepam | 2-4mg IV |
| Hypertension | Labetalol | 20mg IV, then 20-80mg q10min (max 300mg) |
| Alternative | Hydralazine | 5-10mg IV q20min |
| Nicardipine | Infusion | 5-15 mg/hr |
Definition
Overview
Eclampsia is the occurrence of new-onset, generalized tonic-clonic seizures in a woman with preeclampsia, without other identifiable causes for the seizures. It represents a severe end of the hypertensive disorders of pregnancy spectrum and is a life-threatening obstetric emergency requiring immediate treatment and urgent delivery.
Classification
Timing of Onset:
| Type | Timing | Frequency |
|---|---|---|
| Antepartum | Before labor | 50% |
| Intrapartum | During labor | 25% |
| Postpartum | After delivery (up to 6 weeks) | 25% |
By Preeclampsia Severity (Pre-Seizure):
- Preeclampsia without severe features
- Preeclampsia with severe features
- HELLP syndrome
HELLP Syndrome Criteria:
- Hemolysis: Schistocytes, elevated bilirubin, elevated LDH
- ELevated Liver enzymes: AST >70 U/L
- Low Platelets: <100,000/μL
Epidemiology
- Incidence: 1.6-10 per 10,000 deliveries in developed countries; higher in developing
- Maternal mortality: 0-14% in developed countries; up to 15% in developing
- Perinatal mortality: 5-12%
- Recurrence risk: 2% in subsequent pregnancies
- Progression from preeclampsia: <1% with treatment; 2-3% without treatment
Risk Factors
| Category | Risk Factors |
|---|---|
| Pregnancy-related | Nulliparity, multiple gestation, molar pregnancy, hydrops fetalis |
| Underlying conditions | Chronic HTN, renal disease, diabetes, SLE, antiphospholipid syndrome |
| Prior history | Previous preeclampsia/eclampsia, family history |
| Demographic | Extremes of maternal age (<20 or >0), obesity, Black race |
| Partner-related | New partner, limited sperm exposure |
Pathophysiology
Mechanism of Seizure in Eclampsia
Proposed Mechanisms:
- Cerebral vasospasm: In response to severe hypertension
- Cerebral edema: Posterior reversible encephalopathy syndrome (PRES)
- Endothelial dysfunction: Increased permeability of blood-brain barrier
- Microhemorrhages: Hypertensive encephalopathy
Underlying Pathophysiology of Preeclampsia
- Abnormal placentation: Defective trophoblast invasion of spiral arteries
- Placental hypoxia-ischemia: Resulting in release of antiangiogenic factors
- Endothelial dysfunction: sFlt-1 and reduced PlGF disrupt vascular function
- Systemic manifestations: Hypertension, proteinuria, organ dysfunction
- Cerebral involvement: Leads to seizures in eclampsia
Cerebral Changes
- PRES (Posterior Reversible Encephalopathy Syndrome): Vasogenic edema in posterior circulation
- MRI findings: T2/FLAIR hyperintensities in parieto-occipital regions
- Usually reversible with treatment
Clinical Presentation
Prodromal Symptoms (Warning Signs Before Seizure)
| Symptom | Frequency |
|---|---|
| Severe headache | 50-75% |
| Visual disturbances | 20-35% (scotomata, blurred vision, blindness) |
| Epigastric/RUQ pain | 20% (hepatic involvement) |
| Nausea/vomiting | Common |
| Altered mentation | Variable |
Important: 20% of eclamptic seizures occur WITHOUT prodromal symptoms
Seizure Characteristics
Physical Examination
Vital Signs:
Neurological:
Other Findings:
Fetal Status:
Type
Generalized tonic-clonic (grand mal)
Duration
Usually 60-90 seconds
Post-ictal phase
Confusion, agitation, combativeness
Recurrence
Without treatment, recurrent seizures common
Red Flags
Life-Threatening Complications
| Finding | Concern | Action |
|---|---|---|
| Status epilepticus | Refractory seizures | Repeat magnesium, add benzodiazepines |
| Persistent altered consciousness | Intracranial hemorrhage, stroke | Urgent CT head |
| Focal neurological deficits | Stroke, hemorrhage | CT/MRI, neurology |
| Sudden severe headache | Intracranial hemorrhage | CT head |
| DIC or severe thrombocytopenia | HELLP syndrome | Platelets, FFP, delivery |
| Pulmonary edema | Fluid overload, cardiac dysfunction | Diuretics, oxygen, intubation if severe |
| Rigidity + loin pain | Placental abruption | Urgent delivery |
| Fetal bradycardia >0 min | Fetal compromise | Emergent cesarean if doesn't resolve |
Features Atypical for Eclampsia (Consider Alternative Diagnosis)
- Onset before 20 weeks gestation (except molar pregnancy)
- Focal seizures
- Prolonged post-ictal period (>1-2 hours)
- Seizures >48 hours postpartum (late postpartum eclampsia still possible but rare)
- Absence of hypertension and proteinuria (15-20% can have atypical presentation)
Differential Diagnosis
Alternative Causes of Seizures in Pregnancy
| Diagnosis | Distinguishing Features | Key Evaluation |
|---|---|---|
| Epilepsy | Pre-existing history, breakthrough | Antiepileptic levels, history |
| Intracranial hemorrhage | Sudden severe headache, focal signs | CT head |
| Ischemic stroke | Focal deficits | CT/MRI, CT angiography |
| Cerebral venous thrombosis | Headache, focal signs, hypercoagulable | MRV, CT venography |
| Posterior reversible encephalopathy (other causes) | Often similar to eclampsia | MRI |
| Meningitis/encephalitis | Fever, meningismus | LP, CSF analysis |
| Metabolic (hypoglycemia, hyponatremia) | Lab abnormalities | Glucose, electrolytes |
| Drug toxicity | History of drug use | Tox screen |
| Thrombotic thrombocytopenic purpura | Fever, hemolysis, renal failure, neurological | ADAMTS13 activity |
Diagnostic Approach
Clinical Diagnosis
Eclampsia = Preeclampsia + New-Onset Seizures
Preeclampsia criteria (one + proteinuria OR severe features):
- BP ≥140/90 on two occasions ≥4 hours apart (or ≥160/110 once)
- Proteinuria (≥300mg/24h or P/C ratio ≥0.3)
- OR absence of proteinuria with: Thrombocytopenia, elevated LFTs, renal insufficiency, pulmonary edema, cerebral/visual symptoms
Laboratory Workup
| Test | Purpose | Expected Findings |
|---|---|---|
| CBC with platelets | HELLP, DIC | Thrombocytopenia, low Hgb if hemolysis |
| LFTs (AST, ALT) | HELLP, hepatic involvement | Elevated; AST >0 typical in HELLP |
| LDH | Hemolysis | Elevated in HELLP |
| Bilirubin | Hemolysis | May be elevated |
| Creatinine, BUN | Renal function | May be elevated |
| Coagulation studies (PT, aPTT, fibrinogen) | DIC | Prolonged PT/aPTT, low fibrinogen if DIC |
| Uric acid | Preeclampsia severity | Usually elevated |
| Urinalysis or protein/creatinine ratio | Proteinuria | Often ≥2+ protein |
| Blood smear | HELLP confirmation | Schistocytes, helmet cells |
| Type and screen | Prepare for delivery, possible transfusion |
Imaging
CT Head (Indications):
- Atypical features (focal deficits, prolonged altered consciousness)
- Consider before LP to rule out mass/hemorrhage
- Often not needed if classic presentation with rapid response
MRI Brain:
- Shows PRES changes (posterior white matter edema)
- More sensitive than CT
- Not urgently needed for management
Fetal Assessment
- Continuous fetal heart rate monitoring
- Assess for decelerations during/after seizure
- Resolution typically within 3-5 minutes (if doesn't resolve, suspect abruption)
Treatment
Principles of Management
- Secure airway and protect patient: During and after seizure
- Magnesium sulfate: First-line for seizure control and prevention
- Control blood pressure: Prevent cerebrovascular complications
- Stabilize mother: Before delivery
- Deliver: Definitive treatment; timing depends on gestational age and severity
- Monitor for magnesium toxicity: Respiratory depression, areflexia
Immediate Seizure Management
During Active Seizure:
- Protect from injury (side rails, remove obstacles)
- Position on left side (prevents aspiration, improves uterine blood flow)
- Provide oxygen (high-flow)
- Suction as needed
- Prepare magnesium sulfate
Magnesium Sulfate Protocol:
| Phase | Dose | Administration |
|---|---|---|
| Loading | 4-6g IV | Over 15-20 minutes |
| Maintenance | 1-2g/hr IV | Continuous infusion |
| Recurrent seizure on Mg | 2g IV | Over 5 minutes (can give additional 2g) |
Magnesium Monitoring:
| Parameter | Therapeutic | Toxicity Concern |
|---|---|---|
| Serum level | 4-7 mEq/L | > mEq/L |
| Deep tendon reflexes | Present | Absent (first sign of toxicity) |
| Respiratory rate | >2/min | <12/min |
| Urine output | >5-30 mL/hr | Oliguria (Mg excreted renally) |
Magnesium Toxicity Treatment:
- Stop magnesium infusion
- Calcium gluconate: 1g (10 mL of 10%) IV over 3 minutes
- Support respiration (may need intubation)
Second-Line for Refractory Seizures:
| Agent | Dose | Notes |
|---|---|---|
| Lorazepam | 2-4mg IV | If seizures persist despite Mg |
| Phenytoin | 15-20mg/kg IV | Not preferred; Mg superior |
| Propofol or thiopental | If intubated | For SE |
Blood Pressure Management
Target: SBP <160, DBP <110 (prevent stroke, not normalize BP)
| Agent | Initial Dose | Repeat/Titration | Notes |
|---|---|---|---|
| Labetalol | 20mg IV | 20-80mg q10-20min (max 300mg) | First-line; avoid in asthma |
| Hydralazine | 5-10mg IV | Repeat q20min × 3 | Can cause reflex tachycardia |
| Nicardipine | 5mg/hr infusion | Increase by 2.5mg/hr q5-15min (max 15mg/hr) | Good for severe HTN |
| Nifedipine | 10-20mg PO | Repeat in 30min PRN | If IV access delayed |
Avoid: ACE inhibitors, ARBs (teratogenic), nitroprusside (cyanide toxicity to fetus)
Fluid Management
- Cautious IV fluids: 80-100 mL/hr or less
- Avoid fluid overload (risk of pulmonary edema)
- Monitor urine output (target ≥30 mL/hr)
- Maintain foley catheter
Timing of Delivery
Eclampsia = Indication for Delivery
| Gestational Age | Approach |
|---|---|
| ≥34 weeks | Deliver after stabilization |
| <34 weeks | Stabilize, corticosteroids if time permits, then deliver |
| <24 weeks (previable) | Stabilize mother, counsel regarding prognosis |
Mode of Delivery:
- Vaginal preferred if cervix favorable and no other contraindications
- Cesarean for: Non-reassuring fetal status, failed induction, other obstetric indications
- Eclampsia itself is NOT an indication for cesarean
Corticosteroids for Fetal Lung Maturity:
- Betamethasone 12mg IM × 2 doses 24h apart
- Only if safe to delay delivery 24-48 hours (often not possible)
Postpartum Management
- Continue magnesium for 24-48 hours after last seizure
- Continue BP management
- Monitor for HELLP, renal failure, pulmonary edema
- Watch for postpartum eclampsia (can occur up to 6 weeks postpartum)
Disposition
Admission Criteria
- All patients with eclampsia require admission
- Initially to labor and delivery for stabilization and delivery
- ICU admission if:
- Status epilepticus
- Respiratory compromise
- Severe HELLP or DIC
- Need for vasopressor support
- Intubated for airway protection
Post-Delivery (Postpartum) Management
- Continue monitoring for 24-48 hours postpartum
- Continue magnesium prophylaxis
- Most will have improving BP and labs within 48-72 hours
- Late postpartum eclampsia can occur up to 6 weeks
Follow-Up
| Timeframe | Purpose |
|---|---|
| 1-2 weeks postpartum | BP check, symptoms review, proteinuria resolution |
| 6 weeks postpartum | Full postpartum visit, cardiovascular risk counseling |
| Long-term | Cardiology/nephrology if persistent HTN; preconception counseling for future pregnancies |
Patient Education
Condition Explanation
- "Eclampsia is a serious complication of pregnancy involving high blood pressure and seizures."
- "The only cure is to deliver the baby, which is why we're recommending that now."
- "Without treatment, there can be serious harm to you and the baby."
Long-Term Counseling
Recurrence Risk:
- Risk of preeclampsia in future pregnancy: 20-40%
- Risk of eclampsia in future pregnancy: 2%
- Low-dose aspirin starting at 12 weeks in future pregnancies reduces risk
Cardiovascular Health:
- Preeclampsia/eclampsia increases lifetime cardiovascular risk
- Higher risk of: Chronic HTN, heart disease, stroke
- Importance of: Healthy lifestyle, BP monitoring, regular check-ups
Warning Signs for Future Pregnancies
- Severe headache
- Vision changes
- Upper abdominal pain
- Significant swelling
- Decreased fetal movement
Special Populations
HELLP Syndrome
- Occurs in 10-20% of eclampsia cases
- Higher maternal mortality (1-3%)
- Treatment: Stabilize, transfuse as needed, deliver
- Platelet transfusion if <20,000 or <50,000 and bleeding/procedure planned
- Monitor for hepatic complications (subcapsular hematoma, rupture)
Postpartum Eclampsia
- 25% of cases occur postpartum
- Can occur up to 6 weeks after delivery
- Same management: Magnesium, BP control
- Higher index of suspicion needed (patient already "delivered")
Late-Onset Postpartum Eclampsia (>48h Post-Delivery)
- Less common, often presents to ED
- Women may not recognize symptoms as pregnancy-related
- Same treatment applies
Chronic Hypertension with Superimposed Preeclampsia
- Higher baseline risk for eclampsia
- May have resistant hypertension
- Multidisciplinary management
Multiple Gestation
- Higher risk of preeclampsia/eclampsia
- Close monitoring required
- Delivery timing depends on chorionicity and severity
Quality Metrics
Performance Indicators
| Metric | Target | Rationale |
|---|---|---|
| Magnesium as first-line for seizure | 100% | Evidence-based treatment |
| Time to magnesium after seizure | <15 minutes | Rapid treatment |
| BP controlled <160/110 | 100% | Prevent stroke |
| Delivery within 24 hours of eclampsia | >5% | Definitive treatment |
| Magnesium continued 24h postpartum | 100% | Prevent recurrence |
| Documentation of fetal status | 100% | Fetal safety |
Documentation Requirements
- Seizure description (timing, duration, witnessed details)
- Gestational age
- Vital signs trend
- Labs (especially platelet, LFTs)
- Magnesium dosing and levels
- BP management and medications used
- Fetal heart rate monitoring results
- Mode and timing of delivery
- Consultation notes (OB, MFM, ICU if applicable)
Key Clinical Pearls
Diagnostic Pearls
- 20% have seizures without prodromal symptoms: Don't rely on warning signs
- 15-20% can be normotensive: Eclampsia can occur without classic hypertension
- Can occur up to 6 weeks postpartum: Maintain suspicion in postpartum patients
- PRES on MRI: But don't delay treatment for imaging
- Always consider alternative diagnoses: Especially if atypical features
Treatment Pearls
- Magnesium, not benzodiazepines: First-line for eclamptic seizures
- Mg level 4-7 mEq/L is therapeutic: Monitor clinically (reflexes, RR) + levels
- Calcium gluconate for Mg toxicity: Have at bedside
- BP control ≠ normalization: Target <160/110, not normal
- Deliver after stabilization: Don't delay excessively
- Continue Mg 24-48h postpartum: Prevent recurrent seizures
Disposition Pearls
- All eclampsia patients need admission: No outpatient management
- ICU for severe cases: Status epilepticus, HELLP, respiratory compromise
- Postpartum monitoring is essential: Late postpartum seizures can occur
- Long-term cardiovascular counseling: Increased lifetime CV risk
- Plan for future pregnancies: Low-dose aspirin prophylaxis
References
- American College of Obstetricians and Gynecologists. Gestational Hypertension and Preeclampsia. ACOG Practice Bulletin No. 222. Obstet Gynecol. 2020;135(6):e237-e260.
- Altman D, et al. Do women with pre-eclampsia, and their babies, benefit from magnesium sulphate? The Magpie Trial: a randomised placebo-controlled trial. Lancet. 2002;359(9321):1877-1890.
- Sibai BM. Diagnosis, prevention, and management of eclampsia. Obstet Gynecol. 2005;105(2):402-410.
- Chames MC, et al. Late postpartum eclampsia: a preventable disease? Am J Obstet Gynecol. 2002;186(6):1174-1177.
- Brown MA, et al. Hypertensive Disorders of Pregnancy: ISSHP Classification, Diagnosis, and Management Recommendations for International Practice. Hypertension. 2018;72(1):24-43.
- Fishel Bartal M, Sibai BM. Eclampsia in the 21st century. Am J Obstet Gynecol. 2022;226(2S):S1237-S1253.
- NICE Guideline NG133. Hypertension in pregnancy: diagnosis and management. 2019.
- UpToDate. Eclampsia. 2024.