Plasma vitamin values and antiepileptic therapy: Case reports of pregnancy outcomes affected by a neural tube defect
Article first published online: 21 NOV 2006
Copyright © 2006 Wiley-Liss, Inc.
Birth Defects Research Part A: Clinical and Molecular Teratology
Volume 79, Issue 1, pages 62–64, January 2007
How to Cite
Candito, M., Naimi, M., Boisson, C., Rudigoz, J.-C., Gaucherand, P., Guéant, J.-L., Luton, D. and Obberghen, E. V. (2007), Plasma vitamin values and antiepileptic therapy: Case reports of pregnancy outcomes affected by a neural tube defect. Birth Defects Research Part A: Clinical and Molecular Teratology, 79: 62–64. doi: 10.1002/bdra.20318
- Issue published online: 4 JAN 2007
- Article first published online: 21 NOV 2006
- Manuscript Accepted: 5 SEP 2006
- Manuscript Revised: 28 JUL 2006
- Manuscript Received: 23 DEC 2005
- neural tube defects;
- valproic acid;
- vitamin B6;
BACKGROUND: Folic acid supplementation reduces the occurrence of neural tube defects (NTDs); however, it is not clear whether it protects against teratogenic effects of antiepileptic drugs. METHODS: We report the cases of four pregnant women receiving valproic acid therapy, who all had NTD-affected offspring, despite periconceptional 5 mg/day of folic acid supplementation (cases), and investigated homocysteine metabolism, linked with folate metabolism. Their plasma homocysteine, folates, and vitamin B6 and B12 results were compared with values of two other women, who were also receiving valproic acid and folic acid complement, but who had normal pregnancies (valproic acid controls), and values of 40 pregnant women who had normal pregnancies and were not receiving any therapy (controls without therapy). Because of the possible existence of a genetic susceptibility, polymorphisms in homocysteine metabolism were sought. RESULTS: Two cases showed a decreased phosphopyridoxal level, compared with levels in the controls not receiving therapy. The genotype TT (C677T) is an NTD genetic susceptibility, but it was observed in only one valproic acid control. Various polymorphisms were observed in the cases, but were also common in the controls. Several studies have reported that valproic acid therapy lowers vitamin B6 levels. Our case with the greatest decrease in plasma phosphopyridoxal, who was taking periconceptional folic acid plus pyridoxine therapy, had a normal second pregnancy outcome. CONCLUSIONS: In addition to folates, other vitamins, such as vitamin B6, may have played a role in NTDs in our patients taking an antiepileptic drug. Birth Defects Research (Part A) 2007. © 2006 Wiley-Liss, Inc.