Spina Bifida

The brain, spine, and spinal cord are responsible for nearly every function in the body. They’re so important that they are among the first body parts to form. Early in fetal development, they’re collectively known as the neural tube.

In most cases, the neural tube closes completely. However, in people with spina bifida, the neural tube does not form or close all the way. This can cause damage to the spinal cord and nerves.

Some types of spina bifida are mild—they may even go undiagnosed because they don’t cause any symptoms. Other forms of spina bifida are more severe and will require treatment after birth.

Types And Symptoms

There are four main types of spina bifida.

Spina Bifida Occulta 

This is the mildest form of spina bifida. It occurs when one or more bones in the spine (also known as vertebrae) do not form properly.

Because the spinal nerves are not affected, most people with this type of spina bifida don’t experience any signs or symptoms. In fact, some people with spina bifida occulta never even know they have it.

Occasionally, it’s possible to see signs of spina bifida occulta on the skin that covers the spine. These signs may include:

  • A hairy patch
  • A mass of fatty tissue
  • A dimple, birthmark, or collection of blood vessels


Closed Neural Tube Defects

This type of spina bifida occurs when the fat, bones, or protective membranes surrounding the spinal cord do not develop properly.

As with other mild forms of spina bifida, people with closed neural tube defects may not notice any signs or symptoms. If symptoms do occur, they may include:

  • A hairy patch on the skin that covers the spine
  • Bladder problems
  • Bowel problems



In this type of spina bifida, the spinal cord develops normally. However, sacs of spinal fluid and protective membranes (also known as meninges) push through an opening in the neural tube.

In many cases, the sacs are covered by a thin layer of skin. While some people with meningocele do not notice any symptoms, others may experience:

  • Bladder problems
  • Bowel problems



This is the most severe form of spina bifida. Unfortunately, it’s also the most common.

It occurs when the neural tube does not close completely, leaving an opening on the lower or middle back. The spinal cord and surrounding tissues are exposed through the opening, causing partial or complete paralysis of the lower body. Other symptoms include:

  • Bladder problems
  • Bowel problems
  • Hydrocephalus (excess fluid in the brain)
  • Chiari malformation—a problem involving brain tissue pushing into the spinal canal
  • Learning disabilities


While the exact cause of spina bifida is unknown, it’s likely that both genetic and environmental factors (e.g., fever or prolonged hot tub use during pregnancy) both play a role.


Physicians use several diagnostic tests to screen for spina bifida during pregnancy. These include:

  • Alpha-fetoprotein (AFP) blood test: All fetuses produce a type of protein known as alpha-fetoprotein. It’s normal for some of this protein to pass into the mother’s bloodstream. However, a high level of AFP may be a sign of spina bifida. Physicians use a blood test to check the mother’s AFP levels.
  • Ultrasound: An ultrasound is a routine and painless imaging test that helps the physician see the fetus during pregnancy.
  • Amniocentesis: During this test, a physician takes a sample of the amniotic fluid that protects the fetus in the womb. High levels of AFP in the amniotic fluid may be a sign of spina bifida.


While more severe forms of spina bifida are often diagnosed during pregnancy, milder forms are usually diagnosed after a baby is born. In some cases—when spina bifida causes no signs or symptoms—it may never be diagnosed.



Whether or not a child needs treatment for spina bifida depends on the type and severity of his condition. Most children with milder forms of spina bifida don’t need any treatment.

On the other hand, children with myelomeningocele typically require surgery to close the spinal opening and prevent infection. In most cases, surgery is performed within the first few days of a child’s life.

Depending on the child’s symptoms, other treatments may include:

  • Bowel and bladder therapy
  • Assistive devices (braces, crutches, or wheelchairs)
  • Surgery to treat associated disorders, such as hydrocephalus and Chiari malformation
  • Support for learning disabilities


Since genetics are thought to play a role in causing spina bifida, it cannot always be prevented. However, since environmental factors also are thought to play a role, there may be ways to reduce the risk to a fetus. For example. a woman can lower her risk of giving birth to a child with spina bifida by taking folic acid (vitamins) during pregnancy.