We identified women between 16-44 years old who were treated by a University of Michigan Epilepsy provider from 2010-2021, had encounters for pregnancy and epilepsy and were prescribed Levetiracetam. Women that were not seen in the Epilepsy clinic during pregnancy were excluded. Women were identified through an automated query applying these inclusion/exclusion criteria using DataDirect (an in-house program for cohort identification from the electronic medical record). Medical records were then reviewed and data on race/ethnicity, epilepsy diagnosis, levetiracetam levels (before, during and after pregnancy) and seizure frequency (baseline over one year prior to and during pregnancy) were abstracted.

Of 129 women, 24 pregnancies in 24 women with epilepsy using levetiracetam throughout their pregnancy were included. Of these, 18 women were seizure-free at baseline. Nine demonstrating breakthrough seizures showed an average levetiracetam serum level of 13.66 (<1.0 to 29.1), and an average percentage change in serum level of +6.19% (from -149.2% to +170.8%). Of the seizure-free patients at baseline without a breakthrough seizure, the average serum levetiracetam level was 17.48 (<1.0 to 47.7); the average percentage change in level was 85.7% (from -70.44% to +118.1%).

Changes in serum levetiracetam levels during pregnancy are major factors of breakthrough seizures. Seizure-free patients at baseline that remained seizure free maintained higher serum levels of levetiracetam demonstrating higher average percentage increases in their serum levels. Following frequent levetiracetam levels and adjusting dosage accordingly throughout pregnancy will minimize breakthrough seizure frequency.