Blood Test Can Help Prevent Serious Neural Tube Birth Defects Like Spina Bifida

A simple blood test can help prevent neural tube birth defects like spina bifida, a new study reveals.

Neural tube defects are the most common birth defects that affect 300,000 births globally, each year. It is a serious congenital defect of the central nervous system that includes spinal cord, skull and brain. It is one of the most common severely disabling birth defects.

One of the natural forms of vitamin B present in food is folate; on the other hand, folic acid is synthetically produced and is used in fortified foods and supplements. To reduce the risk of neural tube defects, it is important to consume folic acid before and during early pregnancy. Currently, it is recommended that pregnant women should take 400ig (micrograms) of folic acid a day, but the exact amount of folic acid needed to prevent neural tube defects is not known clearly.

A study, conducted earlier in Ireland, revealed that the risk of having a child with neural tube defect is higher in case the concentration of red blood cell folate drops, indicating this could be considered as a biomarker to predict the risk of neural tube defect in a population and take necessary prevention measures.

The researchers worked on data from two population-based studies in China that consisted of 220,000 births and 250 babies with neural tube defects.

To estimate the link between red blood cell folate concentration at the time of completion of neural tube closure and neural tube defect risk, the researchers used mathematical models. They noticed that the risk of neural tube defect was more when red blood cell folate concentration was lower.

The estimated risk dropped at red blood cell folate concentrations above 1,000 nmol/L.  If the red blood cell folate concentration was 1,180 nmol/L, the risk of neural tube defect was 6 per 10,000 births.

"Our results indicate that a red blood cell folate concentration of roughly 1,000 to 1,300 nmol/L might achieve optimal prevention of folate sensitive neural tube defects, with a resulting overall risk of neural tube defect of about 6 per 10,000," said the authors.

This range is applicable to women in various countries and is useful in the development and monitoring of folic acid fortification programs. However, they did not find that exact natural food folate or folic acid intake is necessary to achieve the red blood cells folate concentrations in 1,000-1,300 nmol/L range in any person. 

"Setting 'optimal' or target population red blood cell folate concentration cutoffs will be useful in assessing the need for and monitoring the success of programs for the prevention of folate sensitive neural tube defects," they concluded.

The finding was documented in BMJ-British Medical Journal.