What is the best management approach for a pregnant patient with a history of seizures?

Management of Pregnant Patients with Seizures

Pregnant patients with seizures require immediate emergency medical services activation, continuation of antiepileptic medications (never abrupt discontinuation), avoidance of valproate, and coordinated care between neurology and maternal-fetal medicine with frequent monitoring throughout pregnancy. 1, 2

Immediate Management During Active Seizure

• Activate emergency medical services immediately for any seizure in pregnancy, as this represents a critical medical emergency 1, 2
• Position the patient on their side to minimize aspiration risk and clear surrounding hazards 1
• Do not restrain the patient or place anything in their mouth 1
• Monitor seizure duration carefully—seizures lasting >5 minutes require immediate anticonvulsant intervention 1, 2
• Never give oral medications, food, or liquids during the seizure or if consciousness is impaired 1

Emergency Department Evaluation

Essential Testing

• Check serum glucose and sodium levels immediately 1
• Confirm pregnancy status if unknown 1
• Perform complete neurological examination with attention to focal deficits 1
• Consider lumbar puncture if meningitis or encephalitis is suspected 1
• Obtain toxicology screening if drug exposure is suspected 1

Risk Stratification

• Document whether this is a first-time seizure or recurrent epilepsy 1
• Assess for return to neurological baseline within 5-10 minutes after seizure cessation 1
• Evaluate for seizure-related injuries, respiratory compromise, or trauma 1

Antiepileptic Drug Management

Critical Medication Principles

Never abruptly discontinue antiepileptic medications during pregnancy, as breakthrough seizures pose catastrophic risks to both mother and fetus. 1, 2

• Approximately one-third of women with epilepsy experience increased seizure frequency during pregnancy 1, 2, 3
• Antiepileptic drug levels decline progressively during pregnancy even with constant dosing, requiring frequent monitoring and dose adjustments 1, 4, 5
• Uncontrolled tonic-clonic seizures are more harmful to the fetus than antiepileptic drugs 6

Medication Selection and Safety

Valproate must be avoided or discontinued immediately due to high teratogenic risk, particularly at doses >800 mg/day. 2, 3, 7

• Valproate carries a 10.7% risk of congenital malformations (4-fold increase versus other antiepileptic drugs) and 1-2% risk of neural tube defects 7
• Lamotrigine and levetiracetam have favorable safety profiles and should be preferred 1, 2, 3, 8
• Oxcarbazepine presents a favorable teratogenic profile with serum level monitoring recommended 1, 3
• Aim for monotherapy at the lowest effective dose, as polytherapy increases teratogenic risk 2, 3, 6

Pharmacokinetic Monitoring

• Lamotrigine concentrations may decrease by >50% during pregnancy, requiring dose adjustments 4, 5
• Levetiracetam concentrations may also decline significantly due to increased renal clearance 4, 5
• Monohydroxyoxcarbazepine (active metabolite of oxcarbazepine) may decrease by 30-40% 5
• Monitor drug levels frequently throughout pregnancy, using preconception baseline concentrations as reference 6, 4, 5

Preconception and Prenatal Care

Medication Optimization Before Pregnancy

• Transition from valproate to safer alternatives (levetiracetam or lamotrigine) before conception when possible 2
• Achieve seizure control on the lowest effective dose of a single agent before pregnancy 6, 9
• Establish baseline therapeutic drug levels for reference during pregnancy 4

Folic Acid Supplementation

• Prescribe high-dose folic acid 4 mg daily starting at least one month before conception and continuing through the first trimester 2, 3, 7
• This reduces the risk of neural tube defects, though specific benefit in valproate-exposed pregnancies is unknown 7

Coordinated Care

• Arrange consultation with maternal-fetal medicine specialist and neurologist 1, 2
• Schedule more frequent prenatal visits to monitor both seizure control and pregnancy progression 2
• Admit all pregnant patients presenting with seizures for observation, coordinated care, and fetal monitoring 1

Disposition and Follow-up

• Early seizure recurrence is highest within the first 6 hours (mean 121 minutes), with >85% occurring within 360 minutes 1
• Plan for specialized care during labor and delivery with appropriate monitoring 2
• Encourage breastfeeding in women taking lamotrigine or levetiracetam, with monitoring of the infant for possible adverse effects 3, 8

Common Pitfalls to Avoid

• Failing to activate emergency services for any seizure in pregnancy 1
• Abruptly discontinuing antiepileptic medications due to pregnancy concerns—this can lead to breakthrough seizures with potentially catastrophic consequences 1, 2
• Inadequate monitoring of antiepileptic drug levels during pregnancy, particularly for lamotrigine and levetiracetam 1, 4, 5
• Continuing valproate when equally effective alternatives exist 2, 3, 7
• Failing to adjust medication doses in response to pregnancy-related pharmacokinetic changes 2, 4