Abstract
BACKGROUND:
It is well established that women who have had a pregnancy affected by a neural tube defect (NTD) have an elevated risk of a subsequent NTD‐affected pregnancy and that a high dose (4 mg/day) of folic acid taken around the time of conception prevents most recurrences of NTDs.
METHODS:
We reviewed the literature to identify studies that quantify the reduction in risk if women with a prior‐NTD affected pregnancy consistently take folic acid before and during a subsequent pregnancy and the effectiveness of NTD recurrence prevention programs in increasing the percentage of women who consistently consume folic acid supplements.
RESULTS:
A meta‐analysis of randomized trials of folic acid for the prevention of recurrent NTDs indicates a 69% reduction in recurrence risk if analyzed on an intention‐to‐treat basis and an 87% reduction among those women who took supplements prior to the beginning of pregnancy. Observational studies report reductions in recurrence risk of 85% to 100% among women taking folic acid prior to subsequent pregnancies. The percentage of women who take folic acid prior to a subsequent pregnancy has been reported to vary from 33% to 85%, varying with the demographic background and the intensity of folic acid counseling efforts.
CONCLUSIONS:
Targeted folic acid information and counseling provided to women with an NTD‐affected pregnancy has been demonstrated to substantially reduce the risk of recurrent NTDs and is feasible to implement on a public health basis. Birth Defects Research (Part A) 79:737–742, 2007. © 2007 Wiley‐Liss, Inc.