Neural Tube Defects

Within the first four weeks of pregnancy, the embryo forms and closes a neural tube. This tube becomes the spine and brain of the developing child. If the tube doesn’t close correctly, the baby is said to have a neural tube defect (NTD).

There are two main types of NTD – spina bifida, where the spinal cord isn’t closed properly, and anencephaly, where the brain isn’t closed off. Spina bifida children are paralysed to varying degrees and usually have learning difficulties as well; anencephaly children die during pregnancy or soon afterwards.

NTDs can be tested for at about 16 – 18 weeks of pregnancy, and they catch most cases if they use ultrasound and the triple test.

Who has NTD babies?

Unfortunately, NTD babies can happen to anyone – 95% of cases are in families without a previous history of NTDs.

However, there are some factors that make it more likely for the woman to conceive a NTD baby:

• Having had a NTD baby in a previous pregnancy makes it twenty times more likely subsequent children will have one, too
• Being obese – as defined by a doctor, not just being overweight
• Experiencing high body temperatures in early pregnancy. This could be due to a fever or sitting in a hot spa or sauna (not recommended for pregnant women anyway.)
• Taking some anti-seizure drugs. If you are epilectic or require these drugs for other reasons, discuss whether you need to change medication before getting pregnant.
• Having insulin dependant diabetes
• Hispanic people have a higher rate of NTD

Prevention

As NTDs develop in the first 4 to 6 weeks of pregnancy, they often happen before the woman is even aware of being pregnant so prevention needs to occur before pregnancy.

Obviously, anything that takes you out of the risk groups listed above will cut down the chances of having a NTD baby.

The biggest means of reducing the risk, however, is by simply taking 400 micrograms of folate (or folic acid.)

Daily doses of folic acid in the month before conception and for at least three months after conception reduce the risk of NTD by 70%. That means, that for every 10 children who would have developed a NTD, 7 of them can be prevented with folate.

Considering that about half of all pregnancies are unplanned and that folate is needed so early in pregnancy, it is important that women who may become pregnant take folate daily. Research is also showing other health benefits from taking folate daily so it is in everyone’s interests for this to happen.

Unfortunately, only about one third of women are getting enough folate in their diets. Many foods are now fortified with folate; some cereals actually have the daily requirements in each serve.