Emergency Department Orders for First-Time Seizure in Pregnancy
For a pregnant patient presenting with a first-time seizure in the ED, immediately obtain serum glucose, comprehensive metabolic panel including magnesium and calcium, complete blood count, urine protein, blood pressure measurements, and non-contrast head CT with abdominal shielding—while simultaneously determining if the patient is ≥20 weeks gestation to rule out eclampsia as the primary consideration.
Initial Diagnostic Workup
The evaluation differs critically based on gestational age and whether eclampsia is suspected:
Essential Laboratory Orders
- Serum glucose (hypoglycemia is a reversible cause)
- Comprehensive metabolic panel (electrolyte disturbances, renal function, liver enzymes)
- Magnesium and calcium levels (metabolic causes)
- Complete blood count (infection, thrombocytopenia suggesting HELLP syndrome)
- Urine protein (pre-eclampsia/eclampsia screening if ≥20 weeks)
- Toxicology screen (substance misuse should be considered in all collapse cases) 1
Blood Pressure Monitoring
Serial blood pressure measurements are critical—if the patient is ≥20 weeks gestation, eclampsia must be the primary consideration until proven otherwise 1, 2. Uncontrolled hypertension, particularly systolic hypertension, can lead to intracranial hemorrhage 1.
Neuroimaging
Order non-contrast head CT with appropriate abdominal shielding 3. The evaluation of a pregnant woman with new-onset seizures follows the same protocol as non-pregnant patients 3. This is essential to rule out:
- Intracranial hemorrhage
- Structural brain lesions
- Posterior reversible encephalopathy syndrome (PRES)—the most common cause of status epilepticus in pregnancy (38% of cases) 4
- Cortical venous sinus thrombosis (17% of pregnancy-related SE cases) 4
Critical Clinical Distinctions
Eclampsia vs. Other Causes
- If ≥20 weeks gestation with hypertension and/or proteinuria: Presume eclampsia 2
- If <20 weeks or normotensive with no proteinuria: Evaluate for other etiologies (epilepsy, metabolic, structural, infectious) 1
- Note: 25% of eclamptic seizures occur postpartum 2
Additional Considerations
Check for signs of infection—bacteremia can progress rapidly to septic shock even without fever or elevated white count 1. Consider drug toxicity, particularly if the patient received local anesthetics or magnesium sulfate 1.
Seizure Management Orders
If Eclampsia is Suspected (≥20 weeks, hypertensive)
Magnesium sulfate is the recommended first-line treatment for eclamptic seizures 2, 4. However, recent evidence suggests that if seizures persist despite magnesium, standard antiseizure medications should be added 5. In one study, 4 of 7 eclampsia patients required ASMs in addition to magnesium for seizure control 5.
If Status Epilepticus Develops or Non-Eclamptic Seizure
After benzodiazepines, use fosphenytoin, levetiracetam, or valproate as second-line agents with similar efficacy 6. The ESETT trial demonstrated no significant difference in seizure cessation rates at 60 minutes:
- Levetiracetam: 47%
- Fosphenytoin: 45%
- Valproate: 46%
Levetiracetam has the best safety profile with only 0.7% life-threatening hypotension versus 3.2% with fosphenytoin and 1.6% with valproate 6. Levetiracetam is also the most commonly used antiseizure medication in pregnant women with epilepsy 5.
Common Pitfalls to Avoid
- Don't assume all seizures ≥20 weeks are eclampsia—epilepsy, PRES, CVT, and autoimmune encephalitis must be considered 4
- Don't withhold CT imaging due to pregnancy—use abdominal shielding; the risk of undiagnosed structural pathology far exceeds radiation risk 3
- Don't rely solely on magnesium for all pregnancy-related seizures—if seizures continue, add standard antiseizure medications 5
- Don't forget that drug toxicity (local anesthetics) can cause seizures and cardiovascular collapse 1
Disposition Considerations
Hospitalization is significantly associated with third-trimester presentation (p=0.005) 5. Patients with abnormal neurologic examination, persistent altered mental status, or identified structural/metabolic causes require admission 7. Medication non-compliance is associated with higher seizure frequency and adverse neonatal outcomes 8.