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Spina Bifida


The Manual's Editorial Staff

Last full review/revision Apr 2019| Content last modified Apr 2019
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What is spina bifida?

Spina bifida is a birth defect of the spine. The unborn baby’s spine doesn’t form normally. Sometimes the spinal cord and nerves coming from it are affected. This may cause no problems, or it may cause long-term problems with walking, urinating, and passing stool.

  • Spina bifida affects the middle and lower back

  • A few children also have brain defects

  • Defects range from small to large

  • Small defects usually cause no symptoms

  • Large defects may cause leg weakness and problems walking, curvature of the spine, or bladder problems

  • Damage to the brain or spinal cord is much more likely when the tissue visibly bulges from the back of the baby

  • If parts of the spinal cord are exposed, the baby may develop an infection (meningitis)

Spina Bifida: A Defect of the Spine

In spina bifida, the bones of the spine (vertebrae) do not form normally. Spina bifida can vary in severity.

In occult spinal dysraphism, one or more vertebrae do not form normally, and the spinal cord and the layers of tissues (meninges) surrounding it may also be affected. The only symptom may be a tuft of hair, a dimpling, or a pigmented area on the skin over the defect.

In a meningocele, the meninges protrude through the incompletely formed vertebrae, resulting in a fluid-filled bulge under the skin. The spinal cord is in its normal location.

The most severe type is a meningomyelocele, in which the meninges and spinal cord protrude. The affected area appears raw and red, and the infant is likely to be severely impaired.

Spina Bifida: A Defect of the Spine

What causes spina bifida?

Causes of spina bifida include:

  • Not having enough of the vitamin folic acid before and during pregnancy

  • A genetic disorder

  • Using certain medicines during pregnancy, such as valproate

What are the symptoms of spina bifida?

Many children who have small defects have no symptoms. Most symptoms are from brain damage or spinal cord damage. 

Symptoms include:

  • Too much fluid in the spaces within the brain (hydrocephalus)

  • Learning disabilities

  • Difficulty swallowing

  • Difficulty walking

  • Lack of normal feeling in the skin over the spinal cord

  • Inability or difficulty urinating

  • Frequent urinary tract infections

  • Loss of control over passing stool

How can doctors tell if a baby has spina bifida?

Doctors do a screening during the 2nd trimester of pregnancy. This may include:

How do doctors treat spina bifida?

Usually, doctors do surgery.

  • A team of specialists decide on the type and how severe the defect is, and talk to the family about treatment and care

  • Doctors will treat problems of the bladder, bone, muscle, and other areas

Can spina bifida be prevented?

Doctors recommend that all women who might become pregnant or who are pregnant take the vitamin folic acid (folate). Studies show that folic acid helps prevent spina bifida and similar defects in the unborn baby.

  • Women who have had a baby with spina bifida have a higher chance of having another baby with the same defect, and they should take high-dose folic acid vitamins beginning 3 months before getting pregnant and continuing through the 1st trimester of pregnancy

Talk with your doctor about how much folic acid you should take.

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