MedLines: Neural Tube Defects

By Patience Joseph Mamman


At about the 3rd week of pregnancy, in the first month, a significant development in the embryo begins. Formation of the what is known as the Neural tube begins. This neural tube is the progenitor organ that develops into the brain and spinal cord,in short the nervous system. During this process certain malformations can oocur that leads to what is called Neural Tube Defect.

Neural Tube Defect is said to occur when the neural tube fails to close completely and failure of this closure leads to two main types of neural tube defects which are Spina Bifida and Anencephaly.

  1. Spina Bifida.
    In spina bifida, the fetal spinal column doesn’t close completely. There’s usually a nerve damage that causes at least some paralysis of the legs. The effects of Spina bifida vary from the appearance of a dimpling or tuft of hair at the base of the spine and a minor abnormality of the vertebrae to complete exposure of the spinal cord which is a condition known as myelomeningocele.
  2. Anencephaly
    In this condition, most of the brain tissue and skull do not develop. Babies with anencephaly are usually either stillborn or die shortly after birth.

Symptoms of Neural Tube Defects

Symptoms depend on the severity of the disorder and they include:

  • Paralysis of the legs
  • Abnormalities in the functioning of the bladder and bowels.
  • There could be build up of fluid in the skull known as hydrocephalus.

Causes of Neural Tube Defect

The real cause of neural tube defect is not completely understood but certain factors stand out.

  • Genetic predisposition.
  • Intake of certain types of anticonvulsant drugs during pregnancy.
  • Inadequate intake or deficiency of folic acid and Vit B12.


Neural tube defects can be detected early enough while the fetus is still intrauterine. And some of the ways to diagnose such include:

  • Ultrasound imaging detects almost all types of neural tube defect.
  • Amniotic fluid analysis.
  • Triple blood Test.

In conclusion, pregnant women are usually advised to take lots of folic acid as this serves as a preventive measure to the fetus from developing neural tube defects.