Does pregnancy per se make epilepsy worse?

Objective: To determine whether being pregnant in its own right alters epileptic seizure control. Materials/Methods: Study of 148 pregnancies in women who took no antiepileptic drugs before pregnancy and in at least the earlier half of pregnancy, 69 taking none throughout pregnancy. Results: More women (P < 0.01) had seizures of any type during pregnancy (45.9%) than in the prepregnancy year (34.5%), and also convulsive seizures (30.4% vs 12.3%). After excluding potential confounding factors, viz. late prepregnancy drug withdrawal, treatment resumption in pregnancy possibly preventing seizure recurrence, the figures became seizures of any type 56.6% during and 35.5% before pregnancy and convulsive seizures 39.4% during and 18.2% before pregnancy (both P < 0.01). There was a non-statistically significant greater tendency for seizure control to be lost during pregnancy in genetic generalized than in focal epilepsies (54.2% vs 35.5%). Conclusions: Irrespective of its effects on antiepileptic drug disposition, being pregnant per se seems to impair epileptic seizure control.