Should folic acid be given to women treated with valproic acid and/or carbamazepine?

Fetal exposure to valproic acid;or carbamazepine increases the risk of neural tube defect (NTD). The risk of a mother having a baby with spina bifida has been estimated at 1-2p.100, close to the rate of risk of recurrent cases. No study has evaluated the effect of folic acid in neonates of women treated with :valproic acid or-carbamazepine although the protective effect against NTD has been proven in other populations; Periconceptional folic acid supplementation, 0,4 to 1 mg/day, for at least one month prior to conception and until the date of the second missed menstrual period or later decreases the incidence of a first occurrence of neural tube defect Periconceptional folic acid supplementation, 4 mg/day, decreases the recurrence of NTD in women who had previously had a,child with NTD. It seems pertinent to recommend periconceptional folio acid-supplementation in women treated with carbamazepine or valporic acid. There are very few data in women on wich to base, a decision to advise taking 4 mg/day (as used in recurrence prevention) or low doses of 0,4 mg/day (used in primary prevention).