New-onset epilepsy in women with first time seizures during pregnancy

In women with epilepsy, seizure frequency and severity can be affected during pregnancy by factors such as changes in ASD (anti-seizure drug) metabolism, changes in hormone levels, and medication compliance. Some women with epilepsy experience seizure worsening during pregnancy, while others have an improvement. Most epileptic seizures during pregnancy occur in women with pre-existing epilepsy. Rarely, women develop new-onset seizure-like episodes concerning for epileptic seizures during pregnancy, posing a diagnostic and therapeutic challenge for the physician.

To determine the frequency of new-onset seizures during pregnancy and the clinical course of those with new seizures, we performed a retrospective study of all women with concomitant diagnoses of pregnancy and seizures (excluding eclampsia) at the Johns Hopkins Medical Institutions over a five-year period. We calculated the frequency of events concerning for seizures during pregnancy, including first-lifetime events, and classified these events as epileptic seizures or as seizure mimics. For those with epileptic seizures, we followed up with the patient to determine whether seizures recurred in or after pregnancy, and whether treatment with anti-seizure medication was initiated.

Over a five-year period, 41,869 women received care at Johns Hopkins Medical Institutions during pregnancy. 84 women had at least one event concerning for seizure during their pregnancies. Of these, 11 had no prior history of seizures; 5 of these women were found to have first-time unprovoked epileptic seizures supported by epileptiform abnormalities on EEG. All women delivered at term with no major complications. Four of these women continued to have epileptic seizures after delivery.

New onset seizures during pregnancy were rare. Most women with first-time epileptic seizures during pregnancy also had epileptic seizures after pregnancy, indicating a first presentation of epilepsy.