Neural tube defects are congenital defects of the brain, spine, or spinal cord. They occur during the first month of pregnancy, often before a woman knows she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In spina bifida, the foetus’s spine does not close completely. There is usually nerve damage, which causes at least some paralysis of the legs. In anencephaly, most of the brain and skull do not develop. Children with anencephaly are usually either stillborn or die shortly after birth. Another type of defect, Chiari malformation, causes brain tissue to extend into the spinal canal.
The exact causes of neural tube defects are unknown. You have a higher risk of having a baby with a neural tube defect if you:
- Are obese
- Have poorly controlled diabetes
- Take certain anti-seizure medications
Getting enough folic acid, a type of vitamin B, before and during pregnancy prevents most neural tube defects.
Neural tube defects are usually diagnosed before the baby is born through laboratory or imaging tests. Neural tube defects cannot be cured. The nerve damage and loss of function present at birth are usually irreversible. However, various treatments can sometimes prevent further damage and help with complications.
