Scott D Grosse1, Julianne S Collins. 1. National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
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.
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.
Authors: Timothy J Flood; Chelsea M Rienks; Alina L Flores; Cara T Mai; Barbara K Frohnert; Rachel E Rutkowski; Jane A Evans; Russell S Kirby Journal: Birth Defects Res A Clin Mol Teratol Date: 2016-11
Authors: Lu Ban; Kate M Fleming; Pat Doyle; Liam Smeeth; Richard B Hubbard; Linda Fiaschi; Laila J Tata Journal: PLoS One Date: 2015-07-06 Impact factor: 3.240