Management of Seizures during Pregnancy

1
Management of Seizures during Pregnancy

• Christopher R. Leon-Guerrero MS3

2
Epidemiology

• Seizures are the most frequent major neurologic
  complication encountered in pregnancy
• 15-32 of women with epilepsy will have a seizure
  during pregnancy
• 4-8 chance of major fetal malformations compared
  to 2-3 in the general population
• 10-15 chance of minor fetal malformation
  compared to 5-10 in the general population
• 2-14 risk of fetal death compared to 2-7 in the
  general population

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The Impact of Pregnancy of Seizures
Seizure frequency during pregnancy Increase in
24 Decrease in 23 Unchanged 53
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Seizures vs. Antiepileptic Drugs

• Uncertain as to which is worse during pregnancy
• Women with epilepsy appear to have an increased
  baseline risk of fetal malformations
• Seizures during pregnancy can lead to an
  increased risk of maternal trauma potentially
  leading to fetal injury e.g. abruption, hypoxia
• Increased incidence of depressed APGAR scores,
  low birth weight, diminished head circumference,
  pre-eclampsia and still birth

5
Toxicity of Antiepileptic Drugs
6
Fetal Hydantoin Syndrome

• Constellation of abnormal findings attributed to
  the use of Phenytoin or other anticonvulsants
  during early pregnancy
• Incidence 10-30 of infants born to women taking
  these drugs
• Findings include
• Midline Craniofacial defects
• - Hypertelorism
• - Cleft palate
• - Broad nasal bridge
• Fingernail hypoplasia
• Developmental delay

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Goals of Management

• Prevention of Seizures
• Risk to Benefit Approach
• Monotherapy
• Prenatal Counseling
• Screening throughout Pregnancy

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Prenatal Management

• Ideally, management should begin prior to
  conception.
• If a patient has been seizure-free for 2 years
  consider discontinuing antiepileptic treatment
• If treatment is continued, the woman should use
  the most effective AED for her epilepsy type at
  the lowest possible dose to control seizures
• Patients should be counseled on the potential
  teratogenicity of antiepileptic medications
• A minimum of 4 mg daily of folic acid
  supplementation is important prior to conception
  and during pregnancy in women

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Antenatal Management

• Levels of antiepileptics should be monitored
  throughout pregnancy
• Avoid changing/adding medications during
  pregnancy
• Comprehensive Level II Ultrasound at 18-22 weeks
  is recommended to check for congenital and
  cardiac malformations
• Amniocentesis should be offered
• Vitamin-K 10 mg QDay starting at the 36th week of
  gestation until delivery

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Seizure Disorder vs. Eclampsia

• New onset seizures may occur during the third
  trimester of pregnancy
• Important to consider eclampsia on the
  differential diagnosis
• Management for eclampsia includes
• -blood pressure control with hydralazine or
  labetalol
• -seizure prophylaxis with MgSO4
• -immediate delivery

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Intrapartum Care

• 5 of women with epilepsy will have a seizure
  during labor and delivery
• Monitor antiepileptic drug levels
• Consider seizure prophylaxis with IV
  benzodiazepines or phenytoin
• Manage seizures acutely with 1-2 mg of
  intravenous diazepam then load phenytoin 1 g/1 h.
• Multidisciplinary Approach Maternal Fetal
  Medicine, Neurology, Pediatrics, Anesthesiology

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Post-Partum Care

• Increased risk of neonatal hemorrhage secondary
  to decreased levels of Vitamin K in mothers
  taking phenytoin, phenobarbital and primidone
• Give the newborn Vitamin-K 1 mg IM x1
• Levels of anticonvulsants will rise abruptly in
  the post-partum period
• Newborn is 4x more likely to develop an
  idiopathic epilepsy compared to the general
  population
• Breastfeeding is not contraindicated in patients
  taking anticonvulsants but caution should be
  taken due to sedation of the newborn

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Future Studies

• Genetic Studies to determine which patients are
  at risk
• Algorithmic approach to drug selection
• Better understanding of the pathophysiology of
  seizures
• Long-term outcomes of patients taking
  anti-epileptic medications during pregnancy

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Summary

• Patients should be informed about the pros and
  cons of antiepileptic medications during
  pregnancy
• Additional monitor and screening should be
  considered
• Multidisciplinary approach is essential
• Future studies are needed

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References

• Seizure Disorders in Pregnancy ACOG Educational
  Bulletin. International Journal of Obstetrics
  and Gynecology. 1997(56). 279-286.
• Holmes LB, Harvey EA, Coull BA, et al. The
  Teratogenicity of Anticonvulsant Drugs. The New
  England Journal of Medicine. 2001344(15)1132-113
  8.
• Practice parameter management issues for women
  with epilepsy (summary statement). Report of the
  Quality Standards Subcommittee of the American
  Academy of Neurology. Neurology. 199851944-8.
• Kalviainen R and Tomson T. Optimizing Treatment
  of Epilepsy During Pregnancy. Neurology.
  200667(Suppl 4)S59-S63.