70% of cases of spina bifida are preventable by folic-acid supplementation

Nov 18 2004

A seminar in this week’s issue of THE LANCET discusses the causes, symptoms, and treatments relating to spina bifida, and reinforces an important public-health message for women about to become pregnant: 70% of cases of spina bifida are preventable by folic-acid supplementation around the time of conception and during early pregnancy.

Spina bifida results from failure of fusion of the neural tube (the embryonic form of the brain and spinal cord), and is one of the most common malformations of human structure. The causes of this disorder are varied, including chromosome abnormalities and gene disorders. The cause is not known in most cases.

Laura Mitchell (The Texas A&M University System Health Science Center, USA) and colleagues highlight how up to 70% of spina bifida cases can be prevented by maternal folic acid supplementation around the time of conception. The mechanism underlying this protective effect is unknown, state the authors, but it is likely to include genes that regulate folate transport and metabolism.

The authors also outline how individuals with spina bifida need both surgical and medical management. Although surgical closure of the malformation is generally done in the neonatal period, a randomised clinical trial to assess in utero closure of spina bifida has been initiated in the USA. Medical management is a lifelong necessity for individuals with spina bifida, and should be provided by a multidisciplinary team.

Dr Mitchell concludes: “Spina bifida is the only birth defect for which there have been tremendous successes in both treatment and prevention. Continuing advances in our understanding of the human genome are providing new opportunities to understand the causes of this disorder, and offer the prospect of developing improved strategies for the prevention of spina bifida. Moreover, in utero treatment, although unproven at this time, might improve quality of life for those individuals born with spina bifida.”

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