Understanding Spina Bifida Birth Defects
The neural tube is an embryonic structure that develops into the baby's brain, spinal cord, and tissues. Generally, the neural tube will form very early in the pregnancy and will close up around the 28th week of pregnancy. In babies with spina bifida, the spine does not develop or close as it should.
Spina bifida might cause physical and learning disabilities that range from mild to severe. The severity depends on the size, location, and whether the spinal cord and nerves are affected. For more severe cases, the time and costs to care for the child can be overwhelming for parents.
There are different types of spina bifida based on the severity, type of defect, size, location, and specific complications present in an individual case. The three most common types of spina bifida are:
- Spina bifida occulta: sometimes called the hidden spina bifida, this is the mildest form of spina bifida. With this type, there is a small gap in the spine, but no opening or sac in the back. Most people that have spina bifida occulta are not even aware they have this condition because it usually does not cause any significant disabilities.
- Meningocele: meninges is a type of membrane that surrounds and protects the spinal cord. With this type of spina bifida, the meninges pushes through the opening in the vertebrae and forms a small sac filled with fluid. Although results in a visible sac in the back of the baby, parts of the spinal cord and nerves are not in the sac. Thus, there is little to no nerve damage with this type of spina bifida.
- Myelomeningocele: also known as open spina bifida, myelomeningocele is the most common and severe form of spina bifida. In this type, the sac of fluid comes through an opening in the baby's back and parts of the spinal cord and nerves are actually on this sac and are damaged as a result. This type of spina bifida causes moderate to severe disabilities, including the inability to go to the bathroom, inability to walk, and lack of sensation in the hands and feet.
Spina bifida can be diagnosed during pregnancy or right after the baby is born. The mild forms of spina bifida, such as spina bifida occulta, might not be diagnosed until late childhood or adulthood.
During Pregnancy: During pregnancy, there are several different prenatal screening and diagnostic tests used to check for spina bifida and other birth defects.
- Alpha-Fetoprotein (AFP): A blood test that measures how much AFP, a protein produced by fetus, passes into the mother's bloodstream. High level of AFP is a possible indication that the baby might have spina bifida.
- Ultrasound: A common test that looks at the baby in the uterus with a picture. In some cases, the physician can see whether the baby has spina bifida through an ultrasound. The more severe types are more likely to be caught with this test.
- Amniocentesis: The physician takes a small sample of the amniotic fluid surrounding the baby in the womb. If there are high levels of AFP in the fluid, it might mean that the baby has spina bifida.
After Birth: In some cases, the physician might not be able to diagnose the condition until after the baby is born. This could be because the mother failed to receive prenatal care or the condition failed to show up on the ultrasound. Regardless, after birth, there is often a hairy patch of skin or a dimple on the baby's back. The doctor will use an image scan, including an X-ray, MRI, or CT to get a clearer view of the newborn's spine and bones.
- November 2019: New guidelines on the management of pediatric spina bifida from the Congress of Neurological Surgeons
Doctors are uncertain as to what causes spina bifida. Similar to other birth defects, doctors believe both genetics and environmental factors play a role in causing spina bifida to occur in some babies. However, there are certain precautions women can take before and during pregnancy to lower the risk of having a baby with spina bifida. The precautions include:
- Taking 400 micrograms of folic acid every day.
- Checking with your doctor or pharmacist about any over the counter drugs, vitamins, and supplements you may take during pregnancy.
- Making sure the doctor is aware of any medical conditions such as diabetes and obesity
- Avoiding overheating and avoid things like hot tubs or saunas
- Treating fevers immediately with Tylenol
Spina bifida is a condition that is more common among the White and Hispanic populations. Exactly why and how it occurs in certain babies is not fully understood, but there are some risk factors, including:
- Folate (Folic Acid) Deficiency: folic acid is important to the healthy development of a baby. A folate deficiency during pregnancy increases the risk of spina bifida and other neural tube defects.
- Genetics: a genetic history of neural tube defects in the family makes spina bifida more likely to occur
- Certain medications: certain medications increase the risk of spina bifida such as anti-seizure medications
- Diabetes: Diabetes and abnormal levels of sugar in the blood causes a higher risk of having a baby with spina bifida
- Obesity: pre-pregnancy obesity is correlated with an increased risk of spina bifida and other neural defects.
- Increased body temperature: there is some evidence that shows that hyperthermia or increased body temperature in the early weeks of pregnancy may risk the chance of spina bifida.
If any of these risk factors may be a problem for you, talk to your doctor and pharmacist to take the proper precautions.Treatment
Not everyone with spina bifida requires the same treatment because the complications of the condition vary depending on the location and severity. For instance, people with myelomeningocele and meningocele will need more treatment than people with spina bifida occulta. The most common treatment options for spina bifida include:
- Surgery: often doctors will perform surgery to close the spine gap before the baby is born. Additionally, spina bifida can lead to other complications such as hydrocephalus (fluid in the brain) and tethered spinal cord that requires surgery to correct.
- Physical therapy: severe spina bifida can cause difficulty with walking and getting around. Physical therapy and training can help children with spina bifida to engage in daily normal activities.
- Bowel and Bladder management: in some types of spina bifida, doctors will recommend routine bowel and bladder evaluations and management plans to help reduce the chance of organ damage and illness (recent article on estimating tracking renal function in spina bifida patients)
- Wang, Y, et. al: Differences in Length of Stay and Costs Between Comparable Hospitalizations of Patients With Spina Bifida With or Without Pressure Injuries. Arch Phys Med Rehabil.2019 Aug;100(8):1475-1481.
- Alabi NB, et. al: Surgeries and Health Outcomes Among Patients With Spina Bifida. Pediatrics. 2018 Sep;142(3).
- Oakeshott, P, et. al: Neurological level at birth predicts survival to the mid-40s and urological deaths in open spina bifida: a complete prospective cohort study. Dev Med Child Neurol. 2015 Jul; 57(7): 634–638.