What is Spina Bifida?

Spina bifida is a condition in which the spine and spinal cord of the fetus do not form properly. The term spina bifida means “split spine” or “bifurcated spine.” This condition belongs to a group of birth defects called neural tube defects (NTDs) that affect the baby’s nervous system.

In a developing embryo, the neural tube will eventually form the baby’s spinal cord, brain, and the layers of membranes that envelop them. With spina bifida, a certain part of the neural tube doesn’t close properly, thus, affecting the spinal cord and the backbone that protect the spinal cord.

Birth defects are abnormal changes that happen during fetal development. Examples of other birth defects include cleft lip and Down syndrome.

How Does Spina Bifida Develop?

Spina bifida is a neural tube defect. The neural tube is a structure in the embryo that later forms the baby's brain, spinal cord, and surrounding tissues.

Normally, the neural tube forms and closes early in the pregnancy, usually by the 28th day after conception.

In babies with spina bifida, a portion of the neural tube does not form properly or close completely. This results in a lesion (defect) that can occur anywhere along the length of the spine, but it typically develops in the lower vertebra (at the lower end of the backbone or the small of the back).

Prevalence of Spina Bifida

The Center for Disease Control and Prevention (CDC) reports that spina bifida occurs in about 1,278 newborns, or 1 in every 2,875 births in the U.S. each year. This disorder develops in the first month of pregnancy, often before a woman knows she is pregnant. Spina bifida can be diagnosed after the baby is born when a hairy patch of skin or a dimple in the back is seen. However, spina bifida can be diagnosed accurately before birth using an ultrasound. An ultrasound is recommended in the second trimester (weeks 18-22 of pregnancy) to check for any potential developmental concerns, including spina bifida.

Types of Spina Bifida

Spina bifida can vary in severity from mild to severe. Babies with mild spina bifida may not have any symptoms or need any treatment. On the other hand, severe spina bifida can result in significant damage to the vertebra (bones of the spine) and spinal nerves. An open spina bifida can be closed surgically, but the nerve damage can result in permanent disabilities.

Spina Bifida Occulta

Spina bifida occulta (hidden spina bifida) is the mildest and most common type of spina bifida. It involves a very small part of the spine. The defect is covered by skin, does not cause symptoms, and does not require treatment. Experts estimate 10-20% of the US population have this mild form (spina bifida occulta) and don’t even know it.

Meningocele

Spina bifida meningocele is the rarest type of spina bifida. Babies with meningocele have an opening in their back through which the nerves protrude. These nerves are covered by the meninx or meninges, which are the membranes that surround the spinal cord. Skin covers the sac-like lump in the baby’s back.

Meningocele can be repaired with surgery during infancy. The child is usually left without any lingering neurological problems or only minor disabilities.

Myelomeningocele

Spina bifida myelomeningocele is the most severe form of the disorder. In babies with myelomeningocele, the spinal cord does not develop properly. A part of the underdeveloped spinal cord and brain tissue protrudes through the back in a sac that contains cerebrospinal fluid and blood vessels. This sac is typically not covered by skin, leaving the nerves and tissues exposed.

Around 8 out of 10 infants born with myelomeningocele also have a condition called hydrocephalus, which is a buildup of fluid on the brain. Hydrocephalus develops due to a defect called a Chiari II malformation or Arnold-Chiari malformation at the base of the skull. The excess spinal fluid can put pressure on the brain and cause seizures, blindness, and permanent brain damage if it is not treated. Babies born with myelomeningocele often have paralysis below the level of the spinal cord lesion, affecting their lower limbs and causing bladder and bowel dysfunction. In more severe cases, the trunk and upper limbs are also involved.

To prevent complications, babies with myelomeningocele need to have shunts inserted surgically below their skin. A shunt is a thin tube that helps to drain fluid from the brain into the abdominal cavity.

Note: Spina bifida cystica refers to a protruding sac that may contain meninges (meningocele), the spinal cord (myelocele), or both (myelomeningocele).

Risk Factors and Causes of Spina Bifida

The exact cause of spina bifida is not known, but scientists believe it is a combination of genetic and environmental factors. Some of the risk factors for spina bifida include:

Low folic acid (vitamin B9) in the mother during pregnancy.
Family history of neural tube defects. A genetic counselor can explain the risks to you if one or more family members have spina bifida.
Taking certain medications during pregnancy, such as anti-seizure drugs, especially at higher doses (valproic acid, carbamazepine).
Uncontrolled diabetes in the mother.
Maternal obesity.
Elevated body temperature in early pregnancy due to fever or use of saunas and hot tubs.

Symptoms of Spina Bifida

Symptoms of Spina Bifida Occulta

Small birthmark, dimple, or tuft of hair at the site of the defect in the spine.
Changes in skin color with red or purple skin.
Spina bifida occulta typically does not cause any neurological symptoms.

Rarely children with spina bifida occulta can develop problems during the growth spurt associated with adolescence. The stretching of the nerves during this time causes the spinal cord to become stuck to the spine. This can cause symptoms such as numbness, weakness, and urinary symptoms (bladder infections and lack of bowel and bladder control or incontinence). A simple surgery can be done to relieve the tension in the tethered spinal cord.

Symptoms of Meningocele

The exposed nerves can put the baby at risk of life-threatening infections and cause problems with leg movement and bowel and bladder function. However, in most babies with meningocele, the spinal cord develops with minimal nerve damage.

Symptoms of Myelomeningocele

Weakness, lack of movement of the legs, and problems with walking
Problems with bladder and bowel function
Hydrocephalus (fluid buildup on the brain)

Symptoms in Adults with Spina Bifida

Diagnosis of Spina Bifida

Spina bifida can usually, but not always, be detected during pregnancy with the following screening tests:

Maternal serum alpha-fetoprotein (MSAFP), a blood test done between the 16th and 18th week of pregnancy. About 75% of women carrying a fetus with spina bifida will have high AFP levels.
Ultrasound (sonogram) imaging is the most accurate way to identify problems in the developing baby’s spine.
If maternal serum AFP (MSAFP) and ultrasound are suspicious for spina bifida, your doctor may do an amniocentesis for fetal diagnosis. This is a test in which a needle is used to extract a small amount of amniotic fluid from the sac surrounding the fetus. The fluid is tested for alpha-fetoprotein (AFP). Fetuses with spina bifida tend to have elevated AFP in the amniotic fluid.

Spina Bifida Treatment and Management

How is Spina Bifida Treated?

Treatment of spina bifida depends on the severity. Spina bifida occulta typically does not require any treatment, but spina bifida meningocele and spina bifida meningomyelocele require treatment.

Prenatal Repair: Surgery Before Birth

Prenatal surgery (surgery on the fetus before birth) may be done before the 26th week of pregnancy to repair open neural tube defects in the spinal column. The surgeon opens the mother’s abdomen and uterus (womb) and repairs the unborn baby's spinal cord. This procedure requires open surgery, but the fetal repair can sometimes be done in a minimally invasive manner with a device called a fetoscope.

A myelomeningocele study found that prenatal surgery can reduce the severity of damage to the child’s nervous system, reducing the degree of disability and need for assistive devices later in life. Prenatal repair can also lower the risk of hydrocephalus.

However, surgery on the developing fetus during pregnancy is done only in specialized centers. It carries certain risks, including premature birth. Your healthcare team, including your OB/GYN, maternal-fetal medicine specialist, fetal cardiologist, fetal surgeon, neonatologist, and pediatric neurosurgeon, will discuss the benefits versus risks with you.

Postnatal Surgical Repair: Surgery After Birth

Many babies with a myelomeningocele birth defect are in breech (feet-first) position. Cesarean birth is usually a safer way to deliver a breech baby with a large cyst or sac in the spine.

Spina bifida myelomeningocele (open spina bifida) needs to be surgically repaired within 72 hours of birth to close the opening in the baby's spinal canal. This is necessary to lower the risk of life-threatening infections in the exposed tissues, to protect the spinal cord from further damage, and to reduce the severity of neurological disorders later in life.

During a myelomeningocele repair surgery, a neurosurgeon pushes the exposed nerves and tissue back inside the spine and closes the defect with muscle and skin. They also place a shunt to relieve hydrocephalus.

Long-Term Care and Management of Complications

In children with the most severe form of spina bifida (myelomeningocele), neurological damage occurs before birth. Long-term care is usually necessary from a multispecialty team of healthcare professionals for complications such as leg weakness, bowel and bladder issues, hydrocephalus, and Chiari malformation (hindbrain herniation component). Some of the treatments necessary may include:

Mobility aids such as braces, crutches, walkers, and wheelchairs
Physical therapy and occupational therapy
Management of bowel and bladder issues with medications, medical treatments, or surgery
Surgical treatment of hydrocephalus, such as ventricular shunting to relieve pressure on the brain by allowing cerebrospinal fluid to flow out. Some babies may be candidates for a less invasive procedure known as endoscopic third ventriculostomy.
Treatment and management of other complications, such as tethered cord, orthopedic complications, GI issues, skin complications, and others

Can You Prevent Neural Tube Defects?

You can prevent spina bifida with some simple measures before and during pregnancy, such as:

Living with Spina Bifida

Prognosis and Quality of Life

Children with spina bifida may need lifelong medical care from a team of healthcare professionals, including neurologists, orthopedists, urologists, neurosurgeons, specialists in pediatric surgery, physical therapists, occupational therapists, physical medicine and rehabilitation specialists, social workers, nutritionists, and special education teachers.

Along with the healthcare team, parents and caregivers of children with spina bifida can work together to manage the condition and support the child’s physical, emotional, and social development.

Support Resources

The Spina Bifida Association (SBA) offers local and national resources for children and adults living with spina bifida.
Shine offers information for carers of people with spina bifida and hydrocephalus.
March of Dimes is a good resource for further information on spina bifida.
Centers for Disease Control and Prevention (CDC) offers information on living with spina bifida in different age groups, including infants, toddlers, school-age children, adolescents, and adults.

FAQs About Spina Bifida

Can You Live a Normal Life With Spina Bifida?

Yes, you can live a normal life with spina bifida. The degree to which the condition affects your quality of life depends on its severity. Spina bifida occulta typically does not cause any symptoms, and most people with this type of spina bifida live long, fulfilling independent lives. People with more severe forms of spina bifida and other neural tube defects may require lifelong medical care but can still live fulfilling lives with the right treatment and support.

Can a Child With Spina Bifida Walk?

Yes, many children with spina bifida can walk, but it depends on the severity of the condition and the care they receive. Some children with spina bifida can walk without assistance, while others may need walking aids such as crutches, braces, and walkers.

Children with more severe forms of spina bifida may need to use a wheelchair for mobility.

Can Spina Bifida Be Corrected?

Yes, spina bifida can be corrected with surgery, both before birth (fetal surgery) and after birth (postnatal repair). However, surgery does not reverse any nerve damage that has already occurred.

What Does Spina Bifida Do to a Person?

Spina bifida can affect a person in many ways, including movement, bladder and bowel control, complications related to hydrocephalus (buildup of fluid on the brain), tethered spinal cord, sensory problems, orthopedic issues such as scoliosis, latex allergy, and other health issues.

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