For women of childbearing potential with epilepsy, seizures should be controlled with the smallest dosage of anti-epileptic drug (AED). Treatment with monotherapy should be achieved, if possible.
The possibility of AED withdrawal should be considered in appropriate clinical setting prior to conception, and the AED treatment should be optimized prior to conception. Many pregnancies are unplanned, underscoring the need for constant vigilance in streamlining the treatment regimen.
Prenatal counseling becomes particularly important, in order that both the physician and patient have open communication and realistic expectations about the course and outcome of a potential pregnancy. All women of childbearing potential with epilepsy should be informed about the known rates of teratogenicity of AEDs, possibility of increased seizure frequency during pregnancy, and the risks of the pregnancy and labor.
All of the conventional AEDs are associated with an increased risk of major and minor anomalies in the offspring and are categorized as US Food and Drug Administration class C or D. Polytherapy increases this risk. Valproic acid and carbamazepine are each associated with an increased risk of neural tube defects, and should be avoided by women with a family history of spina bifida. This combination should be avoided, if possible.
When a woman with epilepsy presents with pregnancy, a monotherapy regimen should not be changed if the seizures are well controlled. Reducing the number of AEDs can be considered in case of polytherapy, if the seizures are well controlled. If seizures are poorly controlled, adequate seizure control is the primary goal.
Serum AED levels should be documented prior to conception, and within each trimester. More frequent monitoring may be necessary in case of poorly controlled seizures. If seizures have occurred during pregnancy, therapeutic AED levels should be documented in the late third trimester, prior to delivery. Phenytoin levels should also include an unbound fraction (“free” level); other unbound AED levels are not generally available. The dose adjustment should be made taking the whole clinical picture into account.
Vitamin K 10 mg per day orally should be administered in the last 4 weeks of pregnancy for women taking hepatic enzyme-inducing AEDS (phenytoin, phenobarbital, primidone, carbamazepine, topiramate, and oxcarbazepine). The newborn should receive vitamin K 1 mg intravenously or intramuscularly regardless of maternal AED exposure.
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References and Recommended Reading
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