Dr. (Prof.) Bhupendra Chaudhary, Senior Consultant, Neurologist & Epileptologist
More than a million women with epilepsy are of childbearing age. Each year, 20,000 babies are born to women living with epilepsy. The fetus, or unborn baby, is exposed to anti-seizure medications in one of every 50 pregnancies.
The best care for women with epilepsy during pregnancy aims at achieving complete seizure control while decreasing the fetus’ exposure to the potential harmful effects of anti-seizure medications. This is why the impact of pregnancy on medication levels and seizures is important to understand.
Treatment recommendations
Once pregnant, a woman with epilepsy who is being treated with Anti-epileptic drugs (AEDs) should be followed by an obstetrician who is comfortable with her medical condition and treatment. Pregnant women should have first-trimester serologic and ultrasonographic studies to assess the risk of neural tube defects.
During pregnancy, the monitoring of AED levels will help to maintain seizure control. Lamotrigine metabolism and clearance increases during pregnancy, and understanding the effect of pregnancy on lamotrigine concentrations is particularly important as this drug is being used increasingly in women who are considering pregnancy.
The most marked declines in serum concentrations during pregnancy are seen with lamotrigine, levetiracetam, and oxcarbazepine, but also phenobarbital, phenytoin, topiramate, and zonisamide undergo clinically relevant increase in elimination. The extent to which pregnancy affects AED blood levels varies between individual women and is best controlled by blood level sampling.