[Folic acid and prevention of anomalies of foetal neural tube closing in women treated for epilepsy].Rev Neurol (Paris). 2003 Feb; 159(2):165-70.RN
Anomalies of neural tube closing are serious malformations which are encountered most often in babies of epileptic women treated with anti-epileptic drugs during pregnancy. Dietary supplementation of folic acid has been suggested as a preventive measure in these cases, based on the long suspected association between folic acid deficiency and congenital malformations. Folic acid deficiency usually results from insufficient dietary intake, or increased requirements during pregnancy. Moreover, certain anti-epileptic drugs can reduce the availability of folic acid. In secondary prevention, the protective effect of folic acid has been clearly demonstrated, whilst epidemiological data suggest that such treatment is also useful in primary prevention. With respect to women with epilepsy, there is a clear consensus as to the interest of dietary supplementation with folic acid before conception and during the first three months of pregnancy (the period of organogenesis), particularly given the fact that side-effects are extremely rare. Apart from recurrence prevention, where a dose of 4mg/day is recommended, no standard dosing guidelines exist. We would suggest that this same dose be used for epileptic patients in pregnancy, particularly if they are treated with barbamazepine or valproic acid.