What is Spina Bifida?
Spina bifida is a defect of the central nervous system that develops before birth. The condition arises when an embryo’s neural tube, the tissue that eventually forms the central nervous system, develops incorrectly. The neural tube doesn’t close as it usually does in the first few weeks of pregnancy, resulting in an abnormally formed spinal cord and bones of the spine.
The severity of spina bifida varies depending on how the condition develops. In the mildest cases, the condition may cause no significant health problems. In severe cases, spina bifida can cause life-threatening complications and disabilities.
Types of Spina Bifida
Spina bifida is classified according to the type and severity of deformation of the spinal column. The disorder is divided into three different types:
- Myelomeningocele. This is the most severe type of spina bifida. In this type, the spinal column fails to close in the middle or lower back. The bones of the spine do not form properly, and the spinal cord’s nerve tissue is abnormally exposed. As the spinal cord develops, the nerve tissue pushes through the opening and forms an unprotected sac on the baby’s back. This exposes the sensitive nerve tissue to potential damage and infection.
- Meningocele. In this type of spina bifida, the bones of the spine are malformed, and a fluid-filled sac forms on the baby’s back at the location of the deformation. However, the nerve tissue of the spinal cord does not push into the sac. Because the nerve tissue is less exposed, the risk of severe complications is less than in the case of myelomeningocele.
- Spina bifida occulta. In this type, the spine’s bones develop incorrectly, but no nerve tissue pushes through the opening. No sac forms on the baby’s back, and there are often no significant complications. This type of spina bifida may go undetected.
What Causes Spina Bifida?
Scientists are not sure what causes spina bifida. Genetics, environment, and nutrition of the mother during pregnancy all seem to play a role in the development of spina bifida and other neural tube defects, but the interplay of all these factors is not well understood.
Research has indicated several risk factors that appear to increase the chance of spina bifida and other neural tube defects:
- Folate deficiency. When a mother has a nutritional deficiency of folate (also called vitamin B-9 or folic acid) during pregnancy, her baby’s risk of suffering from spina bifida or other neural tube defects increases.
- Family history. Risk increases in families in which previous children have had spina bifida or other neural tube defects. Risk is also higher when the mother herself has suffered from a neural tube defect. Most cases of spina bifida, however, occur in babies with no family history of the disorder.
- Obesity and Diabetes. Women who are significantly overweight or have uncontrolled high blood sugar are at higher risk of having a baby with spina bifida.
- Exposure to high temperatures. The risk of spina bifida seems to increase if an embryo is exposed to high temperatures during pregnancy. This can occur if the mother has a high fever or uses a sauna or hot tub.
- Drug reactions. Certain anti-seizure medications, such as valproic acid, seem to interfere with the body’s folate processing and increase the risk of neural tube defects when taken by the mother during pregnancy.
Is Spina Bifida Hereditary?
The role that inherited factors play in the risk of spina bifida is unclear. Most cases of the disorder occur in babies with no family history of neural tube defects. However, the fact that risk increases with a family history of neural tube defects suggests that genetics play some role. Genetic factors are also indicated by the fact that the disorder is more common in some populations and less common in others.
In any case, the risk of spina bifida does increase if a baby has a parent or sibling who has been affected by a neural tube defect.
How Is Spina Bifida Detected?
Spina bifida is most often detected before birth. In cases where the spinal column’s deformation is less severe, the condition might go unnoticed until after delivery. In very mild cases that cause no complications, spina bifida occulta might never be detected at all.
Early detection of the defect is essential because, in many cases, it can be treated surgically before birth (prenatally). Studies have shown that children who have undergone prenatal surgery are less likely to require future surgeries and more likely to gain the ability to walk independently.
How Is Spina Bifida Diagnosed?
The diagnostic process for spina bifida typically involves both blood tests and imaging scans. Blood tests are a screening tool to look for the possibility of a neural tube defect, but they do not, on their own, definitively indicate that spina bifida is present. A definitive diagnosis is usually made through imaging.
Initial screening tests measure the level of a chemical called alpha-fetoprotein (AFP) in the mother’s bloodstream. The fetus normally produces this protein, and some amount of it usually crosses through the placenta into the mother’s bloodstream. However, an abnormally high AFP level in the mother may indicate that the baby’s neural tube has not closed correctly.
AFP screening results may not be accurate if, for example, the doctor has misjudged the fetus’s age at the time of the test. If initial screening indicates an abnormally high AFP level, the doctor will likely order follow-up tests to confirm the results.
Amniocentesis involves using a needle to withdraw and test a sample of amniotic fluid from the mother’s uterus. Doctors may recommend this procedure if tests indicate a high AFP level. Amniocentesis does not directly measure the severity of spina bifida, but it may be used to rule out other conditions that may be causing high AFP levels.
Ultrasound imaging scans use high-frequency sound waves to produce a visual image of the fetus. Ultrasound scans can show spina bifida when performed during the second trimester of pregnancy and are the definitive method of diagnosing the defect before the baby is born.
When spina bifida is not detected before birth, doctors may use x-rays, magnetic resonance imaging (MRI), or computerized tomography (CT) to identify the severity of the spinal cord’s malformation and brain after the baby is born.
PLEASE CONSULT A PHYSICIAN FOR MORE INFORMATION.
How Is Spina Bifida Treated?
Treatment for spina bifida usually includes initial treatment of the neural tube defect itself, treatment of complications that arise due to the defect, and therapies to help the child cope with long-term complications and disabilities.
Surgery to repair the neural tube defect may be possible before birth. In this procedure, surgeons open the mother’s uterus and fix the baby’s spinal column directly. Prenatal surgery may reduce the risk of damage to fragile nerve tissues before birth, and children who have had prenatal surgery are less likely to experience some severe complications.
If spina bifida is not detected before birth or prenatal surgery isn’t possible, surgery to repair myelomeningocele may be conducted after birth. Surgery to help prevent fluid accumulation in the brain (hydrocephalus), a common complication of spina bifida, may also be performed.
Treatment for Complications
Surgeries or medications may be required to repair or manage complications caused by spina bifida. Common complications requiring treatment include:
- Bowel and bladder function problems
- Accumulation of fluid in the brain (hydrocephalus)
- Tethered spinal cord
- Mobility problems
- Problems with gastrointestinal function
- Skin problems
Children with spina bifida may benefit from therapy programs, such as physical therapy, occupational therapy, special education, and nutritional support to help them manage the disorder’s complications.
How Does Spina Bifida Progress?
In mild cases, spina bifida may not cause significant complications. Severe cases can lead to complications that affect many different parts of the body.
Potential complications of severe spina bifida include:
- Accumulation of fluid in the brain (hydrocephalus)
- Mobility problems or paralysis caused by impaired nerve function
- Bowel and bladder function problems
- Abnormal bone development
- Chiari malformation type II, a condition in which part of the brain develops abnormally at the base of the skull
- Meningitis, an infection of the membrane surrounding the brain and/or spinal cord
- Tethered spinal cord, a condition in which spinal cord nerves fuse to the tissue around them, often at the sight of surgery to repair the neural tube defect
- Skin infections
- Latex allergies
- Urinary tract infections
- Gastrointestinal disorders
- Learning disabilities
How Is Spina Bifida Prevented?
Women who are pregnant or who could become pregnant can reduce their risk of having a baby with spina bifida or other neural tube defects by proactively addressing several risk factors.
- Ensure an adequate intake of folic acid. The recommended daily dose of folic acid is 400 micrograms (mcg). Women who have had a previous pregnancy with a neural tube defect may be encouraged to take a higher dose. Consult a doctor for guidance.
- Manage diabetes according to your doctor’s instructions, and have blood-sugar levels under control before you become pregnant.
- Take steps to control obesity.
- Avoid hot tubs, saunas, and high-temperature environments during pregnancy. Treat high fevers promptly with the over-the-counter fever reducer acetaminophen.
- Tell your doctor about any medications or dietary supplements you’re taking.
Spina Bifida Caregiver Tips
Parents of children with spina bifida should keep some essential tips in mind:
- Be hopeful. A diagnosis of spina bifida is difficult news for expectant parents to bear. It’s important to remember that most people with spina bifida can lead full, productive lives. Complications of the disorder may not be easy to cope with, but you can look forward to many happy years with your child with the proper support.
- Understand your child’s experience with spina bifida. Every child experiences the disorder differently, and your child’s challenges and opportunities will differ from those of every other child with the condition. Learn all you can about spina bifida in general, as well as your child’s specific circumstances.
- Don’t go it alone. Even though your child’s experience with spina bifida is unique, you and your child will benefit from the support of people who understand the obstacles you face. Find a support group of others who understand what you’re going through, either locally or online.
Spina Bifida Brain Science
Much of the research regarding spina bifida is focused on understanding the genetic component of the disorder. Of particular interest are genes that play a role in the processing of folic acid. A deficiency of the chemical seems to play a vital role in the development of neural tube defects. The most studied of these genes is the MTHFR gene, but several other genes are also associated with folic acid. So far, no consistent link between variations in any of these genes and spina bifida has been found.
Other studies are examining the effectiveness of treatments for spina bifida, especially the differences in long-term prognosis for children who undergo prenatal surgery rather than more traditional postnatal surgery.
Spina Bifida Research
Title: In-Utero Endoscopic Correction of Spina Bifida
Contact: Ramen Chmait, MD
University of Southern California
The purpose of this study is to evaluate the feasibility and effectiveness of performing fetoscopic surgical correction of fetal spina bifida. Two surgical approaches will be utilized: the percutaneous technique versus the laparotomy/uterine exteriorization technique.
Title: Incontinence and Quality of Life in Children With Spina Bifida
Contact: Chantel M. Colavecchia, MD
Riley Hospital for Children
This study aims to develop an innovative, interactive tool for joint use by spina bifida patients and their urologists to identify patients interested in addressing their urinary and fecal incontinence and establish continence goal(s) they would like to achieve. To date, no such tool exists for use by spina bifida patients or urologists. This represents a major paradigm shift in the urologic care of pediatric SB patients. It will give children and families a voice in setting their personal goals for urinary and fecal incontinence, rather than relying on physicians’ traditional clinical targets (e.g., absence of urinary incontinence, 4-hour dry interval). These traditional views fail to reflect the complete patient experience of their ailment by underestimating symptoms and prioritizing only the most severe. This study represents the first time that such a process will be formalized before initiating urological therapy in children with SB.
Title: Fetoscopic Repair of Isolated Fetal Spina Bifida
Contact: Jena Miller, MD
Johns Hopkins University
The purpose of this investigation is to evaluate maternal and fetal outcomes following fetoscopic repair of fetal spina bifida at the Johns Hopkins Hospital.
The hypothesis of this study is that fetoscopic spina bifida repair is feasible and has the same effectiveness as open repair of fetal spina bifida, but with the benefit of significantly lower maternal and fetal complication rates. The fetal benefit of the procedure will be the prenatal repair of spina bifida. The maternal benefit of fetoscopic spina bifida repair will be the avoidance of a large uterine incision. This type of incision increases the risk of uterine rupture and requires that all future deliveries are by cesarean section. The use of the minimally invasive fetoscopic surgical technique may also lower the risk of preterm premature rupture of membranes and preterm birth compared to open fetal surgery. Finally, successful fetoscopic spina bifida repair also makes vaginal delivery possible.