Spontaneous abortion and the prophylactic effect of folic acid supplementation in epileptic women undergoing antiepileptic therapy.
BACKGROUND
Antiepileptic drugs (AEDs) like phenytoin (PHE), carbamazepine (CBZ), barbiturates and valproic acid (VPA) interfere with folic acid absorption and metabolism, which in turn can be the cause of adverse pregnancy outcome.


OBJECTIVE
To study the prophylactic effect of folic acid supplementation with regard to spontaneous abortion and preterm delivery (fetal demise after week 20 of gestational age) in pregnant women receiving AED therapy, as well as benefits of most common dosage and preconceptional commencement.


METHODS
Prospective examination of 104 patients, registered in EURAP from 1999-2004 at a single center and a retrospective analysis of data from our epilepsy databank completed with medical records and patients interviews of the Department of Neurology of Innsbruck University Hospital from 1971 to 1999.


RESULTS
388 pregnancies in 244 patients were analyzed. Pregnancies with folic acid supplementation showed significant reduction of spontaneous abortion. With regard to monotherapies, in the group of women taking VPA, supplementation of folic acid had significant benefit. Other examined monotherapies (CBZ, PHE, and PB) known to interfere with folic acid showed no significant results.


CONCLUSIONS
This study confirms the prophylactic effect of folic acid supplementation on spontaneous abortion. For AED therapy, folic acid supplementation should be part of the therapy of every pregnant epileptic woman, especially for those treated with VPA.
Pittschieler
Sabine
S
Department of Neurology, Medical University Innsbruck, Anichstrasse 35, Innsbruck, Austria.
Brezinka
Christoph
C
Jahn
Beate
B
Trinka
Eugen
E
Unterberger
Iris
I
Dobesberger
Judith
J
Walser
Gerald
G
Auckenthaler
Andrea
A
Embacher
Norbert
N
Bauer
Gerhard
G
Luef
Gerhard
G
D000022:Abortion, Spontaneous / Q000139:chemically induced* / Q000188:drug therapy / Q000517:prevention & control*; D000328:Adult; D000927:Anticonvulsants / Q000009:adverse effects*; D019587:Dietary Supplements; D004827:Epilepsy / Q000188:drug therapy* / Q000453:epidemiology; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage*; D006801:Humans; D011247:Pregnancy; D047928:Premature Birth / Q000139:chemically induced / Q000188:drug therapy / Q000517:prevention & control; D011446:Prospective Studies; D012189:Retrospective Studies
D000927:Anticonvulsants; D005492:Folic Acid