EPILEPSY

• Epilepsy complicates approximately 0.5-1% of all pregnancies (1).

• Women with epilepsy tend to undergo more obstetric interventions and labor inductions (20.
• Fetuses of epileptic mothers have a two- to threefold increased risk of congenital malformations (3,4):
• Neural tube defects.
• Cleft lip or palate.
• No pathognomonic congenital heart defect, but most prevalent defects include ASD, VSD, Tetralogy of Fallot, coarctation of the aorta, patent ductus arteriosus and pulmonary stenosis (5).
• Seizures in pregnancy (6):
• 25% of epileptic women experience an increase in seizure activity during pregnancy (thought to be due to sub-therapeutic levels of anti-seizure medication during pregnancy, possible due to variations in drug absorption and tissue distribution, variations in drug metabolism and hyperemesis).
• 25% experience decreased seizure activity during pregnancy.
• 50% experience no change in seizure activity during pregnancy.
• The relationship between maternal seizures and fetal malformations is controversial, however recent studies conclude that seizures during normal pregnancy does not increase the risk of congenital malformations in the fetus. Seizure induced abdominal trauma can result in fetal injury. Fetal generalized tonic-clonic seizures may cause fetal hypoxia and acidosis secondary to placental insufficiency or maternal hypoxia (7). The effects of hypoxic episodes during embryogenesis remains uncertain, however at least one study reports a correlation between first-trimester seizures and an increased risk of congenital malformations (8).
• Anti-epileptic drugs and congenital malformations.
• Anticonvulsant drugs and their effect on the fetus (1,2).

REFERENCES

1. Hiilesman VK, Teramno K, Granstrom ML et.al. Serum folate concentrations during pregnancy in women with epilepsy: relation to antiepileptic drug concentrations, number of seizures, and fetal outcome. BMJ 1983;287:577.
2. Nelson KB, Ellenberg JH. Maternal seizure disorder,outcome of pregnancy and neurologic abnormalities in children. Neurology 1982;32:257.
3. Durner M, Greenberg DA, Delgado-Escueta AV. Is there a genetic relationship between epilepsy and birth defects. Neurology 1992;42 (suppl 5):63.
4. Swartjies JM, van Geijn HP. Pregnancy and epilepsy. Eur J Obstet Gynecol Reprod Biol 1998;76:3.
5. Pennell PB. Epilepsy. In: Cohen WR (ed): Complications of Pregnancy, ed 5. Philadelphia, Lippincott Williams & Williams 2000:p487.
6. Schmidt D: The effect of pregnancy on the natural history of epilepsy: review of the literature. In: Janz D, Bossi L, Dam M et.al. (eds). Epilepsy, Pregnancy and the child. New York, Raven Press 1982:p3
7. Zahn CA, Morrell MJ, Collins SD et.al. Management issues for women with epilepsy: a review of the literature. Neurology 1998;51:949.
8. Lindout D, Meinardi H, Meijer JWA et.al. Antiepileptic drugs and teratogenesis in two consecutive cohorts: Changes in prescription policy paralled by changes in patterns of malformations. Neurology 1992;42(suppl 5):94.