Background: In pregnant women with epilepsy the use of antiepileptic drugs may increase the risk of harming the foetus. For the treating neurologist it may be challenging to find a balance between optimal seizure control and the lowest possible drug dosage. The aim of this study was to assess the prevalence and type of congenital malformations in children exposed to antiepileptic drugs during pregnancy.
Material and method: In Norway we have prospectively followed 813 pregnancies in women with epilepsy as part of an international cohort study. The women had three check-ups during the pregnancy, and the children were followed up twice during their first year of life.
Results: We found a total of 34 congenital malformations in the children, of which 12 were heart defects, yielding a malformation rate of 4.5%. Six of the malformations (18%) were detected prenatally, 20 (59%) were reported immediately after birth, and eight (24%) were discovered during the child's first year of life.
Interpretation: Our study shows that 95.5%.of the women included who used antiepileptic drugs during pregnancy gave birth to a healthy child. This Norwegian cohort is too small to evaluate the teratogenic risk associated with the individual drugs.