Variations in Seizure Frequency During Pregnancy and Postpartum by Epilepsy Type

Abstract

Objective:To assess whether increased seizure frequency during pregnancy and post-partum is influenced by epilepsy type, seizure location, and antiseizure medications.Methods:Clinical data was collected in a longitudinal prospective database of pregnant women with epilepsy at Brigham and Women’s Hospital. Within each individual participant, baseline seizure frequency was calculated for the 9 months preconception, and it was determined if seizure frequency increased during pregnancy or the postpartum period. Seizure frequency was calculated for each 4-week interval during pregnancy. Generalized estimating equations for logistic regression were applied.Results:Ninety-nine patients contributing 114 pregnancies were included from 2013-2018. Increased seizure frequency occurred more often during pregnancies of women with focal versus generalized epilepsy (21.1% vs 5.3%, OR 4.70; 95% CI (1.00, 22.00); p = 0.0497). Among women with focal epilepsy, increased seizure frequency occurred more often in those with frontal lobe epilepsy (OR 8.00; 95 % CI (2.19, 29.21); p = 0.0017). There was no difference in seizure worsening in the postpartum period between focal and generalized (11.1% vs 9.1%, p=0.4478), or frontal and other focal (18.8% vs 6.0%; p=0.1478) epilepsy groups. Pregnancies on polytherapy had higher odds of seizure worsening compared to monotherapy (OR = 8.36, 95% CI = (2.07, 33.84), p = 0.0029), regardless of the medication or epilepsy type. A lack of preconception seizure freedom was also associated with increased seizure frequency during pregnancy (OR = 6.418; p = 0.0076).Conclusion:Women with focal epilepsy have higher likelihood of seizure worsening during pregnancy compared to women with generalized epilepsy; frontal lobe epilepsy poses an especially elevated risk. Polytherapy and lack of preconception seizure freedom are additional predictors for an increased likelihood of seizure worsening.