Prospective, case-control study on the effect of pregnancy on seizure frequency in women with epilepsy.

To evaluate if pregnancy induces a change in seizure frequency and in percentage of subjects remaining seizure-free. This is a prospective case-control study conducted in our tertiary epilepsy centre. Controls were matched 2:1 with the cases for relevant clinical parameters. Cases had to be referred to our centre for at least 9 months before-pregnancy, during pregnancy and the-9-months-after-birth. Controls were followed for the correspondent periods of time: named respectively control period 1-2-3. Seizure frequency was defined as "improved" if there was a 50 % of reduction, "worsened" if there was a 50 % of increase, and "unchanged" in the rest of cases. We recruited 36 cases and 72 controls [in both group mean age was 28 years, partial epilepsy (80.6 %), generalized epilepsy (19.4 %)]; 30 cases and 60 controls were seizure-free before pregnancy and in period 1, respectively. During pregnancy 72 % of cases remained "unchanged" while 8 and 19 % respectively "improved" and "worsened"; moreover, there was no statistical difference in the number of seizure-free patients and in the monthly seizure frequencies. No differences were found in controls. In this prospective case-control study, pregnancy does not affect seizure frequency in women with epilepsy.