The control of treated generalized and focal epilepsies during pregnancy.

Objectives: To examine factors contributing to failure to achieve full seizure control during pregnancy in women with anti-seizure medication (ASM) treated generalized epilepsy compared with focal epilepsy.

Results: Full seizure control was not attained in 51.4% of 1223 pregnancies of women with focal epilepsies in the Australian Pregnancy Register, and in 38.7% of 1026 pregnancies in women with generalized epilepsy (P < 0.05). For convulsive seizures only, the corresponding figures of 20.8% and 22.9% were reasonably similar. Where seizures had occurred in the pre-pregnancy year, 82.5% of the focal epilepsy pregnancies were seizure affected, and 70.1% of the generalized epilepsy ones (P < 0.05). Where the pre-pregnancy year was seizure free, the corresponding figures were 22.6% and 16.4% (P < 0.05), a roughly four-fold lower rate. Maternal age, epilepsy onset age, and epilepsy duration also differed between the focal and generalized epilepsy pregnancies. Multivariate regression analysis showed that generalized epilepsy and younger maternal age were associated with statistically significant decreased risks of seizure-affected pregnancy, and having seizure-affected pre-pregnancy years with an increased risk. However, for convulsive seizures only, the risk of seizure-affected pregnancy appeared increased in generalized epilepsy.

Conclusions: The risk of seizure-affected pregnancy appears lower in women with generalized epilepsy, independently of pre-pregnancy seizure control, itself a major determinant of the risk. The risk of having only convulsive seizures in pregnancy was not lower in generalized epilepsy than in focal epilepsy. ASM therapy seemed less effective in controlling focal than generalized epileptic seizures during pregnancy.