Periconceptional supplementation with folate and/or multivitamins for preventing neural tube defects

[Intervention Review]
Periconceptional supplementation with folate and/or multivitamins for preventing neural tube defects

Judith Lumley1, Lyn Watson2, Max Watson3, Carol Bower4

1Mother and Child Health Research, La Trobe University, Melbourne, Australia. 2Centre for the Study of Mothers' and Children's Health, La Trobe University, Carlton, Australia. 3Centre for Adolescent Health, Royal Children's Hospital, Parkville, Australia. 4Institute for Child Health Research, The University of Western Australia, West Perth, Australia

Contact address: Judith Lumley, Mother and Child Health Research, La Trobe University, 324-328 Little Lonsdale Street, Melbourne, Victoria, 3000, Australia. j.lumley@latrobe.edu.au. (Editorial group: Cochrane Pregnancy and Childbirth Group.)

Cochrane Database of Systematic Reviews, Issue 1, 2009 (Status in this issue: Edited, commented)
Copyright © 2009 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
DOI: 10.1002/14651858.CD001056
This version first published online: 23 July 2001 in Issue 3, 2001. Re-published online with edits: 21 January 2009 in Issue 1, 2009. Last assessed as up-to-date: 28 April 2001. (Help document - Dates and Statuses explained).

This record should be cited as: Lumley J, Watson L, Watson M, Bower C. Periconceptional supplementation with folate and/or multivitamins for preventing neural tube defects. Cochrane Database of Systematic Reviews 2001, Issue 3. Art. No.: CD001056. DOI: 10.1002/14651858.CD001056.
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Abstract


Background
Neural tube defects arise during the development of the brain and spinal cord.


Objectives
The objective of this review was to assess the effects of increased consumption of folate or multivitamins on the prevalence of neural tube defects periconceptionally (that is before pregnancy and in the first two months of pregnancy).


Search strategy
We searched the Cochrane Pregnancy and Childbirth Group trials register. Date of last search: April 2001.


Selection criteria
Randomised and quasi-randomised trials comparing periconceptional supplementation by multivitamins with placebo, folate with placebo, or multivitamins with folate; different dosages of multivitamins or folate; prepregnancy dietary advice and counselling in primary care settings to increase the consumption of folate-rich foods, or folate-fortified foods, with standard care; increased intensity of information provision with standard public health dissemination.


Data collection and analysis
Two reviewers assessed trial quality and extracted data.


Main results
Four trials of supplementation involving 6425 women were included. The trials all addressed the question of supplementation and they were of variable quality. Periconceptional folate supplementation reduced the incidence of neural tube defects (relative risk 0.28, 95% confidence interval 0.13 to 0.58). Folate supplementation did not significantly increase miscarriage, ectopic pregnancy or stillbirth, although there was a possible increase in multiple gestation. Multivitamins alone were not associated with prevention of neural tube defects and did not produce additional preventive effects when given with folate.

One dissemination trial, a community randomised trial, was identified involving six communities, matched in pairs, and where 1206 women of child-bearing age were interviewed following the dissemination intervention. This showed that the provision of printed material increased the awareness of the folate/neural tube defects association by 4%, (odds ratio 1.37, 95% confidence interval 1.33 to 1.42).


Authors' conclusions
Periconceptional folate supplementation has a strong protective effect against neural tube defects. Information about folate should be made more widely available throughout the health and education systems. Women whose fetuses or babies have neural tube defects should be advised of the risk of recurrence in a subsequent pregnancy and offered continuing folate supplementation. The benefits and risks of fortifying basic food stuffs, such as flour, with added folate remain unresolved.


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Plain language summary

Periconceptional supplementation with folate and/or multivitamins for preventing neural tube defects
Supplements of multivitamins or folate before pregnancy and during the first two months help protect against neural tube defects.

The neural tube is the structure from which a baby's brain and spinal cord develop. Neural tube defects (NTDs) are a group of abnormalities that occur in the spine or brain of the baby during pregnancy, causing severe mental and physical disability. The review of trials found that folate, taken as a supplement before pregnancy and in the first two months, is effective in protecting against neural tube defects. Folate did not increase risk of miscarriage, ectopic pregnancy (pregnancy outside the uterus) or stillbirth. Folate may increase the chance of multiple pregnancies. Multivitamins alone do not give protection against NTDs.






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