All women taking antiepileptic drugs at conception are eligible for inclusion whether the indication for treatment is epilepsy or other disorders. Recruitment is carried out by Reporting physicians after obtaining informed consent as required by the Ethics Committee of the individual country.
To ensure anonymity, each case is identified with only the date of birth of the mother and the first three letters of her surname. To avoid selection bias, only pregnancies enrolled before foetal outcome is known and within week 16 of gestation contribute to the prospective study.
Retrospective cases are also collected as they may provide valuable information but are not included in the comparative risk evaluation.