The reasons why the neural type (the tube that forms into the brain and spinal cord in a fetus) does not develop properly are not completely understood. These congenital defects are thought to be the result of numerous genetic, nutritional, and environmental triggers. Research is continuing in this area in an attempt to find answers that will help prevent neural tube defects like Spina Bifida and Fetal Anencephaly. Here are some of the possible causes (or risk factors) for neural tube defects that have been linked through scientific study and experience.
1. Genetics provide an indicator of likelihood. If a couple has had a child with neural tube defects in the past, they are at a much higher risk to have another child with neural tube defects. Identical twins are more likely to have neural tube defects as well.
2. Studies have shown a link between the amount of folic acid pregnant women consume (especially during the four weeks prior to and the four weeks immediately after conception. A lack of folic acid increases the risk of neural tube defects in the infant. Women of childbearing age should get at least 400 mcg of folic acid each day, and more if they have a medical condition or are taking medications which disrupt the absorption of folic acid.
3. Certain epilepsy medications have been proven to increase the risk of neural tube defects. This is thought to occur because anti-seizure (anti-convulsion) pharmaceuticals interfere with folic acid absorption.
4. Women with diabetes who do not control their blood sugar levels while pregnant are also at a higher risk of neural tube defects, like Spina Bifida.
5. A high fever in the mother early on in the pregnancy has also been linked to an increased occurrence of neural tube defects.
6. Women who are obese (body mass index of over 30) are more likely to have a child with neural tube defects than those that are within the correct body mass range.
7. Smoking while pregnant has been linked to giving birth to a baby with neural tube defects. Secondhand smoke inhalation is also an increased risk factor.
8. About 55 to 70 percent of neural tube defects occur in female children. So, gender also predisposes an infant to higher or lower risk.
Though these are increased risk factors or possible causes of neural tube defects, the research is not completely clear. The overwhelming majority of neural tube defects occur with no clear cause determined.