Spina Bifida

What is spina bifida?

Spina bifida is a neural tube defect that frequently occurs in families.  Spina bifida occurs because of an abnormality of the development of the spinal cord that occurs in the first trimester of pregnancy. Within the first 4 weeks after a fetus is conceived, the backbone and membranes that cover and protect the spinal cord and spine does not form and close properly. This can result in an opening anywhere along the spine and may cause damage to the spinal cord and nerves. The defect may be associated with a protrusion of the membrane covering the spinal cord (meninges) alone, called a meningocele, or with some neural elements, called a meningomyelocele. Or the defect may not be noticed until later in life.

Spina bifida can cause physical and mental disabilities ranging from mild to severe, depending on the size and location of the opening in the spine, and whether the spinal cord and nerves are affected.¹

The three most common types of spina bifida are as follows:

Myelomeningocele, in which a sac of fluid containing part of the spinal cord and nerves comes through an opening in the infant’s back, causing nerve damage. Also called “open spina bifida,” this condition causes moderate to severe disabilities, such as problems going to the bathroom, loss of feeling in the legs or feet, and paralysis in the legs.

Meningocele, in which a sac of fluid without the spinal cord comes through an opening in the infant’s back. This type of spina bifida can cause minor disabilities, but there is usually little or no nerve damage.

Spina Bifida Occulta, the mildest type of spina bifida, in which there is a small gap in the spine but no opening or sac on the back. Some infants have a dimple, hairy patch, dark spot, or swelling at the affected place on the back, but the spinal cord and the nerves usually are not damaged. This type of spina bifida usually does not cause any disabilities. Often, spina bifida occulta is not discovered until late childhood or adulthood and sometimes not at all. This is why it is sometimes called “hidden” spina bifida.

About 1,500 infants are born with spina bifida each year in the United States.¹

Anyone can give birth to an infant with spina bifida. However, parents who already have had a child with spina bifida or another neural tube defect have a 4% increased risk of having a second child with spina bifida. Parents of two children with spina bifida have about a 10% chance of having another child with this condition. When one parent has spina bifida, there is about a 4% chance that his or her child also will have it.²

Women who are obese, have poorly controlled diabetes, or take certain antiseizure medications are at greater risk of having a child with spina bifida.^2,3

Scientists believe that spina bifida is caused by a combination of genetic and environmental factors, such as the mother’s nutrition. Research has shown that getting enough folic acid (a B vitamin) before and during pregnancy can prevent most cases of spina bifida.¹

Doctors diagnose spina bifida before or after the infant is born. Spina bifida occulta might not be identified until late childhood or adulthood, or it might not be identified at all.

During Pregnancy

Screening tests can check for spina bifida and other birth defects.

• Blood tests. A “triple screen” examines blood in several ways to look for neural tube defects, such as spina bifida, and other issues. One of these tests measures AFP, or alpha-fetoprotein, which the fetus produces. A high AFP level might mean that the child has spina bifida.
• Amniocentesis. The doctor uses a long needle to obtain some of the amniotic fluid surrounding the fetus in the womb. The fluid can be tested for high levels of AFP, which can mean that the fetus has spina bifida.
• Ultrasound. This technology allows doctors to look at and take pictures of the fetus while it is inside the mother’s womb. Often, spina bifida can be identified through ultrasound.

After the Child Is Born

Sometimes spina bifida is discovered only after the infant is born, especially if the mother did not have prenatal tests or if the ultrasound could not give a clear picture of the spine. Sometimes there is a hairy patch, dimple, dark spot, or swelling on the infant’s back, at the site of the gap in the spine. A doctor can examine the infant’s spine and bones in the back using an image scan such as an X-ray, MRI, or CT.

There is no cure for spina bifida, but there are treatments for a wide array of related conditions. Visit the section on treatments for more information.

Health issues are different for each person with spina bifida. Open spina bifida (myelomeningocele)—in which the spinal cord is exposed—tends to cause more severe problems.¹

Hydrocephalus

Many infants born with spina bifida get extra fluid in and around the brain, a condition called hydrocephalus, or water on the brain. The extra fluid can cause swelling of the head, which may lead to brain injury.

Chiari II Malformation

The brains of most children with open spina bifida are positioned abnormally. The lower part of the brain rests farther down than normal, partially in the upper spinal canal. The cerebrospinal fluid can get blocked and cause hydrocephalus. While most affected children have no other symptoms, a few may have upper body weakness and trouble breathing and swallowing.

Tethered Spinal Cord

Typically, the bottom of the spinal cord floats freely in the spinal canal, but for many people with spina bifida, the spinal cord is attached to the spinal canal. Thus, the spinal cord stretches as a person grows, and this stretching can cause spinal nerve damage. The person might have back pain, scoliosis (crooked spine), weakness in the legs and feet, bladder or bowel control problems, and other issues.

Paralysis, Mobility Limitations

People with spina bifida high on the back (near the head, for instance) might not be able to move their legs. People with spina bifida low on the back (near the hips, for example) might have some leg mobility and be able to walk unassisted or with crutches, braces, or walkers.

Lack of Bladder and Bowel Control

People with spina bifida often cannot control their bladder and bowel movements. They also can develop urinary tract infections.

Latex Allergy

Many people with spina bifida—possibly three-quarters of those with the condition—are allergic to latex, or natural rubber. While researchers still don’t entirely understand why the rate in those with spina bifida is so high, some experts believe such an allergy can be caused by frequent exposure to latex, which is common for people with spina bifida who have shunts and have had many surgeries.²

Learning Disabilities

While at least 80% of children with open spina bifida do not have learning deficiencies, some do have learning problems.³

Other Conditions

Some people with open spina bifida have additional physical and psychological conditions, including digestive, vision, sexual, social, and emotional problems; obesity; and depression.

Open Spina Bifida

An infant with open spina bifida (myelomeningocele), in which the spinal cord is exposed, can have surgery to close the hole in the back before birth or within the first few days after birth.

Hydrocephalus

If an infant with spina bifida has hydrocephalus (water on the brain), a surgeon can implant a shunt—a small hollow tube to drain the extra fluid and relieve pressure on the brain. The shunt may need to be replaced during childhood.

Tethered Spinal Cord

For a child with this condition, in which the spinal cord is attached to the spinal canal and stretches as the child grows, surgery can separate the spinal cord from surrounding tissue, allowing the child to regain his or her usual level of functioning.

Paralysis, Mobility Limitations

People with spina bifida use different ways to get around, according to their needs. They may be able to walk without assistance, or they may use braces, crutches, walkers, or wheelchairs.

Urinary Tract Infections, Lack of Bladder and Bowel Control

People with open spina bifida often have nerve damage that prevents the bladder from completely emptying a condition that can cause urinary tract infections and kidney damage. The child or parent can address this problem by inserting a plastic tube called a catheter into the bladder several times a day to allow the bladder to empty fully. Medications, injections, and surgery can also help address incontinence issues and preserve kidney and bladder function for the long term. Children with spina bifida should see a urologist (a doctor who specializes in urinary tract problems) regularly.