Spina Bifida

What is spina bifida?

Spina bifida is a birth disorder in which the spine doesn’t fully develop. In the first month of pregnancy, a group of cells normally forms the “neural tube,” which is a structure that eventually develops into the brain and spinal cord. In spina bifida, the neural tube doesn’t close completely and some of the bones of the spine do not close in the back. These openings can occur anywhere along the spine and damage the spinal cord and nerves.

Spina bifida is one of a group of developmental issues called "neural tube defects." Neural tube problems happen early in pregnancy when the neural tube does not form as it normally should.

Often, if there are problems with the spine during development, there are also issues with the brain. This is because the neural tube closes first in the middle, and then the closing progresses upward and downward like a zipper that starts closing in the middle and moves to the ends. So, if an issue prevents the spine from forming correctly, it can also affect the part of the brain that is developing at that time.

Each person with spina bifida has different abilities and health challenges. A baby born with spina bifida may have nerve damage, and some will have learning or intellectual disabilities. There is no cure for spina bifida. However, most people with spina bifida lead long lives.

Types of spina bifida

There are four types of spina bifida: occulta, closed neural tube defects, meningocele, and myelomeningocele. The symptoms of spina bifida are different from person to person, depending on the type and severity of the problems in brain and spinal cord development. Most cases are mild and do not need special treatment. 

Occulta

Occulta is the mildest and most common type of spina bifida. It happens when one or more bones in the spinal column (called vertebrae) do not form correctly. This type is called “occulta,” (meaning “hidden”) because a layer of skin covers and hides the opening in the spine. Occulta usually shows no symptoms, and doctors often find it by accident on an x-ray or similar test. 

Closed neural tube defects

Closed neural tube defects are a diverse group of disorders. These disorders happen when the spine has abnormal forms of fat, bone, or protective layers that cover the spinal cord (called meninges). Many of these neural tube defects require surgery in childhood. People with this type of spina bifida may have leg weakness and trouble controlling their bowels and bladder. These issues may change or get worse as children grow. It is important to work closely with the child’s medical team and check in often about any changes in symptoms. 

Meningocele

Meningocele happens when the meninges stick out through the spine and expose a sac of spinal fluid on the back. This sac contains no nerves and may or may not be covered by a layer of skin. People with meningocele may have minor symptoms.

Myelomeningocele

Myelomeningocele is the most severe form of spina bifida. This happens when an opening in the spine exposes part of the spinal cord or nerves through a sac that sticks out from the spinal cord. The meninges may or may not cover the sac. The opening can be closed through a surgery while the baby is in the mother’s uterus, or shortly after the baby is born. Most people born with myelomeningocele experience changes in brain structure, leg weakness, and problems with their bladder and bowels.

Myelomeningocele is often called a "snowflake condition" because no two people with the condition are the same. But generally, if the opening in the spine is lower down the back, the person will experience fewer symptoms. 

Spina bifida complications

There are a few complications that can affect people with any type of spina bifida. These include:

Abnormal sensation or paralysis

This happens most often with closed neural tube defects and myelomeningocele. People with paralysis and abnormal sensation will often have weak legs and core muscles and may have numbness in their groin, feet, or legs. A person may notice this numbness more on one side of the body. These issues don’t get better with age, but symptoms are usually less severe if the opening is in the lower spine. People with these types of spina bifida may lose strength, feeling, and mobility as they age. Some can walk on their own, while others may need leg braces, walkers, crutches, or wheelchairs.

Tethered cord syndrome

Tethered cord syndrome can happen with any type of spina bifida, though it’s rare in the mildest type (spina bifida occulta). This happens when scar-like tissue pulls on the spinal cord and nerves float freely. This can damage the nerves, reduce feeling and strength, and affect bowel and bladder control. Surgery to free the cord is often successful.

Chiari II malformation and hydrocephalus

Some people with myelomeningocele have complications like chiari II malformation, which happens when parts of the brain push down into the neck or spinal canal. People may also have hydrocephalus, an abnormal buildup of fluid in the brain, which can put pressure on the brain. People with myelomeningocele require close follow-up with doctors throughout their lives to make sure they can function well and prevent complications like kidney failure.

Learning disabilities 

Children with myelomeningocele may have learning disabilities, such as:

• Difficulty paying attention and understanding concepts
• Impaired motor skills and memory
• Challenges with organization and problem solving

Incontinence

Most people with myelomeningocele and closed neural tube defects experience incontinence because these conditions affect the nerves at the bottom of the spine that control bowel and bladder function. Many people need special routines or help to manage these functions.

Other complications

As people with myelomeningocele and neural tube defects age, they may experience other health issues, including:

• Skin ulcers
• Low bone mineral density
• Fertility problems (in men)
• Obesity 
• Kidney failure
• Early puberty 
• Sleep apnea
• Depression

Who is more likely to get spina bifida?

Anyone can give birth to a baby with spina bifida. Scientists don’t know the exact cause of spina bifida, but they think genetics, nutrition, and the environment may play a part.

Parents can pass on spina bifida to their children. Parents who have already had a child with a neural tube defect, including spina bifida, have a slightly increased risk of having another child with spina bifida. And if one parent has spina bifida, there is an increased chance that his or her child will also have it. 

Additionally, women who have diabetes that isn’t well managed, or who are taking certain antiseizure medications (especially valproate, which also is used in the treatment of headaches and bipolar disorder), are at greater risk of having a child with spina bifida. Not getting enough folic acid daily is another risk factor. Researchers are still working to understand the role that genetics, the environment, and nutrition play in the development of spina bifida. 

How is spina bifida diagnosed and treated?

Diagnosing spina bifida

In the U.S., most cases of spina bifida are diagnosed prenatally, meaning before the baby is born. Some mild cases might not be found until after birth. Very mild forms of spina bifida may go unnoticed, or a doctor may only find them during tests for other conditions.

Prenatal Diagnosis

There are a few ways to check for spina bifida during pregnancy.

One is maternal serum alpha fetoprotein (MSAFP) screening. This is a blood sample test that shows the levels of a protein called alpha-fetoprotein (AFP) made by the fetus. A person who is 16 to 18 weeks pregnant can get this test. High levels of this protein may show that the fetus has spina bifida or another neural tube defect, but more tests may be needed for confirmation. This test may be performed alone or as part of a larger screening for birth defects. 

A doctor may also do an ultrasound, which uses sound waves to create images of the developing baby. Ultrasounds can accurately detect spina bifida, especially during the second trimester (around 18-22 weeks). 

A doctor may also do amniocentesis. This uses a sample of the amniotic fluid around the fetus to test for protein levels that may indicate neural tube defects or genetic disorders.

Postnatal Diagnosis

Closed neural tube defects are often found at birth when the baby has a visible buildup of fatty tissue (a bubble), a tuft or clump of hair, or a small dimple or birthmark on the skin where the spine is affected. Spina bifida occulta is usually found when a person gets x-rays for another reason later in life.

Sometimes, regular prenatal tests do not find myelomeningocele and meningocele. The baby will be diagnosed when they are born with a “bubble” on its back. Babies with myelomeningocele and closed neural tube defects may have muscle weakness in their feet, hips, and legs. Mild cases of spina bifida (occulta and some forms of closed neural tube defects) that are not diagnosed during prenatal testing may be found after the baby is born using ultrasound or x-ray of their spine.

Treating Spina Bifida

Treatment depends on the type of spina bifida a person has. 

• Myelomeningocele and meningocele require surgery shortly after a baby is born to close the opening and prevent infection. Many babies with myelomeningocele have hydrocephalus and will need a shunt placed to drain this fluid. 
• Children with a closed neural tube defect may need surgery to prevent more medical complications from developing, such as weakness and bowel and bladder problems. 
• Generally, people with spina bifida occulta will not need treatment.

Prenatal Surgery

Doctors may perform surgery on the mother and baby to close the defect in the developing spine while the fetus is still in the womb. This can protect the spinal cord from ongoing damage. 

Surgery does not fix any lost brain function, but might stop further damage during the rest of the pregnancy. However, prenatal surgery has some risks for both the fetus and the mother.

An NIH study showed that babies with prenatal surgery have better outcomes than surgery after a baby is born. This surgery can reduce the need to drain brain fluid and increase the chances that a child can walk on their own later on.

Postnatal Surgery

In treating myelomeningocele and meningocele, a baby that didn’t have prenatal surgery will likely have surgery within the first few days of life. This will allow a doctor to close the defect and lessen the chance of infection or further damage to the nerves and spinal cord.

Treatments for Bowel and Bladder Problems

Treating a child’s bladder and bowel issues typically begins soon after birth. Children with myelomeningocele and some closed neural tube defects may have damage to the lowest spinal nerves which control how the bowel and bladder work. A doctor will monitor their kidneys closely to prevent them from failing after medication or surgery. It is important to have regular care with a spina bifida specialty clinic to develop a safe bowel and bladder program for a child.

Assistive Devices

Some individuals with myelomeningocele or closed neural tube defects may need devices to help them move or walk. These include:

• Braces
• Walkers
• Crutches
• Wheelchairs

These children usually have delays with walking and movement, so a doctor may recommend physical therapy early on to improve their strength and function.

Preventing spina bifida and neural tube defects

Folic acid (folate) is an important vitamin for the healthy development of a fetus. While taking folic acid can’t guarantee a healthy baby, it helps reduce the risk of neural tube defects. Studies show that pregnant people and those preparing for pregnancy can significantly lower the chances of having a child with a neural tube defect when they add folic acid to their diet. Doctors recommended that anyone preparing for pregnancy take a daily vitamin supplement with 400 micrograms of folic acid before and during pregnancy. 

Those who have had a child with spina bifida or another neural tube defect, as well as those who have spina bifida, are at higher risk for having another child with a neural tube defect. They should consult with a doctor about taking a higher prescribed dose of folic acid when they are trying to become pregnant and during pregnancy.

Foods that are high in folic acid include:

• Dark green leafy vegetables
• Egg yolks
• Some fruits (like banana, citrus, and papaya)

Many foods, such as some breakfast cereals, enriched breads, flours, pastas, rice, and other grains —have folic acid added to them. Most multivitamins also contain the recommended amount of folic acid. 

What are the latest updates on spina bifida?

The National Institute of Neurological Disorders and Stroke (NINDS), one of the National Institutes of Health (NIH), is a primary federal supporter of research on brain and nervous system disorders like spina bifida. In addition to NINDS, other NIH Institutes support research on spina bifida and neural tube defects. NINDS supports many kinds of research on spina bifida, including genetic causes and new treatments like surgeries and medications.

Genetic studies

In one study funded by NINDS, scientists are looking into the genetic reasons behind neural tube defects. The study aims to find out which genes can make someone more likely to have these defects. They are also investigating how genes work during healthy neural tube closure to learn more about how the human nervous system develops. 

In addition, NINDS-supported scientists are identifying and studying how specific genes affect neural tube closure. The goal is to improve clinical care, treatment, and genetic counseling.

Other scientists are studying genetic risk factors for spina bifida, especially those that may lower the effectiveness of folic acid in preventing it. This study will shed light on how folic acid prevents spina bifida and may lead to improvements in folate supplements. 

Developmental studies

NINDS carries out and funds many basic research studies on how the brain and nervous system develop. These studies help us understand neural tube defects such as spina bifida, and offer hope for new treatments and prevention methods for this and other birth defects.

Surgery

The Management of Myelomeningocele Study (MOMS) showed that prenatal surgery had significant benefit for the developing baby. NINDS-funded researchers are also working on new techniques, like stem cell patches and tissue engineering to improve prenatal repair of spinal defects.

New treatments

A current study aims to develop a new medicine to help people with bowel and bladder retention problems due to spinal cord injuries and diseases like spina bifida and other illnesses. Another study is looking into the use of a neuroprotective hydrogel paired with a structure to support the bone. This may help protect the affected part of a fetus’s spinal cord during the pregnancy. 

More research efforts

For more information on research about spina bifida, check NIH RePORTER a searchable database of current and past research projects funded by NIH and other federal agencies. RePORTER also has links to publications and resources from these projects.

How can I or my loved one help improve care for people with spina bifida?

Clinical trials increase our understanding of spina bifida with the goal of improving how doctors treat it. Consider participating in a clinical trial so clinicians and scientists can learn more about spina bifida and related disorders. Clinical research with human participants helps researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease. 

All types of participants are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities. This helps make sure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them. 

For information about participating in clinical research visit the NINDS Clinical Trials site and NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with spina bifida at Clinicaltrials.gov, a database of current and past federal and private clinical studies.