Spina Bifida

Overview

Spina bifida is a birth defect that mainly affects the spine. During the first month of pregnancy, a group of cells 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, causing the spine and surrounding tissues to develop abnormally.

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.

There’s no cure for spina bifida, but most people with the condition live long and productive lives.

Types of Spina Bifida

• Occulta is the mildest and most common form, where one or more spine bones (vertebrae) don’t form correctly, but a layer of skin covers the opening. It rarely causes symptoms.
• Closed neural tube defects are a diverse group of defects in which the spine may have growths of fat, bone, or the membranes (meninges) covering the spinal cord. Many patients need surgery in childhood. It may cause leg weakness and trouble with stool and urine control
• Meningocele occurs when a sac of spinal fluid pushes through the spine. The sac contains no nerves and may or may not be covered by skin. It often leads to mild symptoms.
• Myelomeningocele is the most severe form of spina bifida, where parts of the spinal cord or nerves are exposed through an opening in the spine. Most people with myelomeningocele have changes in brain structure, leg weakness, and bladder and bowel problems. No two people with the condition are the same.

Signs and Symptoms

Symptoms may be different based on the type and seriousness of the condition.

• Abnormal sensation or paralysis: People with closed neural tube defects and myelomeningocele often have some weakness in their legs and core muscles, as well as loss of feeling in the groin, feet, or legs. Symptoms are usually less severe if the opening is lower on the spine. Nerve damage means that strength and feeling do not improve over time.
• Chiari II malformation: In this condition, parts of the brain (including the brain stem and cerebellum) push downward into the spinal canal or neck area. If symptoms occur, this pressure on the spinal cord can cause trouble with breathing, swallowing, and arm weakness.
• Hydrocephalus: This is a buildup of fluid around the brain that puts pressure on it. Most people with myelomeningocele have hydrocephalus.
• Meningitis: This is an infection of the meninges, the tissues covering the brain. Sometimes people with shunts develop meningitis. This can cause brain injury and may be life-threatening.
• Tethered cord syndrome: This is where the spinal cord becomes stuck to tissue around it and stretches as a person grows. This can cause back pain, scoliosis, weakness in the legs and feet, and problems controlling the bladder or bowels.
• Bowel and bladder incontinence: Most people with myelomeningocele and closed neural tube defects lose control of their bladder or bowels (incontinence) because the nerves at the bottom of the spine do not work properly.
• Learning disabilities: Children with myelomeningocele may have trouble paying attention, understanding concepts, controlling their movements, remembering things, and organizing or solving problems.
• Latex allergy: Many people with spina bifida are allergic to latex, or natural rubber. This may be caused by repeated exposure to latex during surgeries or medical care, which is common for people with spina bifida.
• Other complications: As people with myelomeningocele get older, they may develop skin sores, weak bones, trouble with male fertility, obesity, kidney failure, early puberty, sleep apnea, and depression.

Causes and Risk Factors

The exact cause of spina bifida is unknown. Scientists believe genetic, nutritional, and environmental factors play a role.

Risk factors include:

• Having a parent with spina bifida
• Having already had one child with a neural tube defect increases risk; having more than one child with spina bifida further increases the risk

Maternal risk factors during pregnancy include:

• Having poorly controlled diabetes
• Taking certain anti-seizure medicines, especially valproate (also used to treat headaches and bipolar disorder)
• Having low folic acid levels
• Having obesity

Researchers are still working to understand the roles that genetics, the environment, and nutrition play in the development of spina bifida.

Prevention Guidance

Folic acid (folate) is an important vitamin for the healthy development of a fetus. While taking folic acid cannot guarantee a healthy baby, studies show that people who are pregnant or plan to become pregnant who add folic acid to their diets can significantly lower the risk of having a child with a neural tube defect.

Doctors recommend that anyone preparing for pregnancy take a daily vitamin supplement with 400 micrograms of folic acid each day before and during early pregnancy.

Some people are at higher risk and should talk to a doctor about taking a larger prescribed dose of folic acid. This includes people who have spina bifida themselves, have had a child with spina bifida, or have had a pregnancy affected by any neural tube defect.

Foods high in folic acid include:

• Dark green leafy vegetables
• Egg yolks
• Some fruits, such as banana, citrus, and papaya

Many foods — such as some breakfast cereals, enriched breads, flours, pastas, rice, and other grain products — are now fortified with folic acid. Most multivitamins also contain the recommended amount of folic acid.

Diagnosis

In the United States, most cases of spina bifida are diagnosed before birth. Some mild cases may not be found until after birth. Very mild forms may go unnoticed, or a doctor may find them only during tests for other conditions.

Diagnosis During Pregnancy

• Maternal serum alpha fetoprotein (MSAFP) screening: At 16–18 weeks of pregnancy, a doctor takes a sample of the mother’s blood to measure the level of alpha-fetoprotein (AFP), a protein made naturally by the fetus and placenta. Abnormally high levels of AFP may indicate that the fetus has spina bifida or another neural tube defect. A high AFP level alone is not enough to confirm a neural tube defect, and additional testing may be needed.
• Ultrasound: A fetal ultrasound uses high-frequency sound waves to create images of the developing baby. It is highly accurate in diagnosing spina bifida, especially during the second trimester (around 18–22 weeks).
• Amniocentesis: A doctor removes a sample of the liquid surrounding the baby (amniotic fluid) and tests it for protein levels that may indicate a neural tube defect or genetic disorders.

Diagnosis After Birth

Doctors often find closed neural tube defects at birth when the baby has a visible buildup of fatty tissue, a tuft or clump of hair, a small dimple, or a birthmark on the skin at the site of the spinal malformation. Doctors usually find spina bifida occulta when a person gets X-rays for another reason.

In rare cases, doctors may not diagnose myelomeningocele and meningocele during routine prenatal tests. Mild cases not diagnosed prenatally may be found after birth using ultrasound or X-ray of the spine.

Doctors may use magnetic resonance imaging (MRI) or computed tomography (CT) to get a clearer view of the spinal cord and vertebrae. A head ultrasound, CT, or MRI may be requested to look for hydrocephalus.

Treatment and Management

Treatments can help manage related conditions. The right approach depends on the type of spina bifida a person has.

• People with spina bifida occulta generally do not need treatment.
• Children with closed neural tube defects may need surgery to prevent further complications such as weakness and bowel and bladder problems.
• Myelomeningocele and meningocele require surgery shortly after birth to close the opening and prevent infection.

Prenatal Surgery

During prenatal surgery, surgeons open the mother’s abdomen and uterus to close the abnormal opening over the developing baby’s spinal cord. The Management of Myelomeningocele Study (MOMS) showed that prenatal surgery to close the spinal cord defect improved outcomes compared to postnatal surgery. Data from the 2012 study showed that prenatal surgery reduced the need to drain fluid from the brain, improved mobility, and increased the chances that a child would be able to walk independently. This study was funded by the National Institutes of Health (NIH).

Prenatal surgery cannot restore nerve function that was already lost, but it may prevent further damage during the rest of the pregnancy. The procedure carries some risk for both the fetus and the mother, including an increased chance of preterm birth.

Postnatal Surgery

A baby born with myelomeningocele or meningocele who did not have prenatal surgery will have surgery within the first few days of life to close the defect and reduce the risk of infection or further nerve damage.

Treating Hydrocephalus

Most people with myelomeningocele have hydrocephalus and will need a shunt placed as an infant. Surgeons implant a shunt, a small hollow tube— in the brain to drain excess fluid into the abdomen, where the body absorbs it. Another option is an endoscopic third ventriculostomy (ETV), a procedure that creates a new path for fluid to flow. Doctors may need to perform multiple surgeries if the shunt becomes clogged, infected, or disconnected.

Treating Bladder and Bowel Problems

Treatment for bladder and bowel problems typically begins soon after birth. Most children with myelomeningocele will need to drain their bladders with a catheter 4–6 times a day to stay dry and prevent kidney damage. Doctors closely monitor the kidneys so they can prescribe medicines or perform surgeries to prevent kidney failure. Medicines, injections, and surgery can also help address incontinence and preserve kidney and bladder function over the long term. Children with spina bifida should see a urologist regularly.

To prevent bowel accidents, many people with myelomeningocele use rectal medicines or large-volume enemas to have planned bowel movements. Close follow-up with a spina bifida specialty clinic is recommended to develop a safe bowel and bladder program.

Treating Tethered Cord Syndrome

Surgery to free the spinal cord from surrounding tissue can help prevent further nerve damage from getting worse and is often successful.

Treating Chiari II Malformation

Surgeons sometimes need to reduce pressure in the area affected by Chiari II malformation.

Treating Orthopedic Issues

Some children with myelomeningocele and closed neural tube defects need surgery to improve the alignment of their feet, legs, or spine.

Assistive Devices

Some people with myelomeningocele or closed neural tube defects need assistive devices for mobility. These may include:

• Braces
• Walkers
• Crutches
• Wheelchairs

The location of the defect on the spine often determines which devices are needed. Children with myelomeningocele usually have some degree of delayed mobility and are referred to physical therapists early on to maximize their strength and function.

Living With Spina Bifida

People with myelomeningocele require close follow-up with doctors throughout their lives to maximize function and prevent complications such as kidney failure.

Doctors recommend an individualized education plan for all children with myelomeningocele.

Find Clinical Trials

Clinical trials uncover better ways to prevent, diagnose, treat, and understand diseases and conditions. To ensure results apply to everyone, volunteers of all ages, sexes, and backgrounds, including both healthy individuals and those with specific medical conditions, are needed. Find clinical trials on spina bifida.

Find Treatment

People with spina bifida should have regular follow-ups at a specialty clinic. The Spina Bifida Association’s list of clinics can help you find a clinic near you.

Community Support

• Spina Bifida Association provides resources for healthcare providers, patients, and their families, including a research page, list of clinics, and latex information.
• March of Dimes supports research on neural tube defects and other congenital anomalies, prematurity, and infant health.
  • March of Dimes: Neural Tube Defects provides information on the most common neural tube defects, their risks, and prevention
• International Conference on Neural Tube Defects is an NIH-supported conference that brings together researchers interested in the causes, consequences, and prevention of neural tube defects.
• U.S. Preventive Services Task Force: Folic Acid for the Prevention of Neural Tube Defects provides the latest recommendations on folic acid use.
• The Centers for Disease Control and Prevention offers a series of articles and resources on Living with Spina Bifida at different stages of life.

Note: This resource list is for informational purposes only. It is not comprehensive, and an organization’s inclusion does not constitute an endorsement by NIH. 

Research Information

The National Institutes of Health (NIH) is the largest public funder of biomedical research in the world. NIH invests most of its budget in medical research seeking to enhance life and to reduce illness and disability. NIH-funded research has led to breakthroughs and new treatments helping people live longer, healthier lives, and building the research foundation that drives discovery.

NIH is the leading federal supporter of research on brain and nervous system disorders like spina bifida. NIH plays a leading role, along with the Centers for Disease Control and Prevention (CDC), in distributing federal funding for spina bifida research.

Genetic Studies

NIH-supported scientists are working to identify and evaluate genes involved in neural tube defects, with the goal of improving clinical care, treatment, and genetic counseling. Other scientists are studying genetic risk factors for spina bifida, especially those that reduce the effectiveness of folic acid in preventing it. NIH-supported researchers are studying the specific genetic activity that drives fetal development and what happens when the neural tube fails to form completely.

Developmental Studies

NIH supports basic research studies to understand how the brain and nervous system develop. NIH supports research evaluating the cognitive, motor, and social development of people with spina bifida across infancy, childhood, and adolescence.

Surgery Research

The Management of Myelomeningocele Study (MOMS), discussed in the Treatment section, showed significant benefit to the developing baby from prenatal surgery. NIH-funded researchers are now building on these results through new techniques including stem cell patches and tissue engineering. A follow-up study, MOMS2, is now underway.

Find NIH-funded research projects using NIH RePORTER, a searchable database of current and past research projects supported by NIH and other federal agencies.