Variations in Seizure Frequency During Pregnancy and Postpartum by Epilepsy Type.

Abstract

To assess whether increased seizure frequency during pregnancy and postpartum is influenced by epilepsy type, seizure location, and antiseizure medications. Clinical data were 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 before conception, and whether seizure frequency increased during pregnancy or the postpartum period was determined. Seizure frequency was calculated for each 4-week interval during pregnancy. Generalized estimating equations for logistic regression were applied. Ninety-nine patients contributing 114 pregnancies were included from 2013 to 2018. Increased seizure frequency occurred more often during pregnancies of women with focal vs generalized epilepsy (21.1% vs 5.3%, odds ratio [OR] 4.70, 95% confidence interval [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 the 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). 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.