Spina Bifida

Spina Bifida (Myelomeningocele)

Spina bifida literally means “cleft spine.” It occurs in roughly three of every 10,000 live births in the U.S., making it the most common birth defect of the central nervous system.

Myelomeningocele, or open neural tube defect (NTD), is the most severe and most common form of spina bifida. It occurs when the spinal cord or other neural elements are exposed by an opening in the spine. This results in partial or complete paralysis of the parts of the body below the opening.

An NTD may occur anywhere along the length of the spine, though it is commonly located at the lower back at the lumbar and sacral vertebrae.

Patients with spina bifida and other NTDs have abnormal function of the spinal cord and nerves in the involved area of the spine. Therefore, it is common for these patients to have abnormal function of their bladder, bowels and legs.

Hydrocephalus, characterized by fluid in the brain, is also common in a baby with a NTD. Hydrocephalus is thought to occur because abnormalities in the back of the brain and spinal column block circulation of the fluid that surrounds the brain (cerebrospinal fluid).

Symptoms and Causes

The exact cause of neural tube defects remains unknown. Scientists think that genes, nutrition and environmental factors all play a role. Research indicates that insufficient folic acid – a common B vitamin – in the mother plays a role in causing spina bifida and other neural tube defects.

Women who already have a child with spina bifida, who have spina bifida themselves, or who have already had a pregnancy affected by any neural tube defect are at greater risk of having another child with a neural tube defect.

Diagnosis

Spina bifida and other NTDs are most often diagnosed during a routine second trimester ultrasound. The most common symptom visible is a fluid-filled sac on the back – protruding from the spinal canal, most often at the base of the spine.

Other tests that may be used to diagnose spina bifida and its severity include maternal serum alpha fetoprotein (MSAFP) screening, fetal ultrasound or amniocentesis.

In less severe cases, a neural tube defect may not be detected until the baby is born.

Treatments

Doctors at Texas Children’s Fetal Center will initially perform a thorough evaluation of your pregnancy. You will meet with pediatric neurosurgeons and pediatricians who specialize in the long-term care of babies with spina bifida. They will review the diagnosis, the range of possible outcomes and treatment options.

Surgery after birth: The NTD can be repaired through surgery in the first few days of life, but many babies develop hydrocephalus and require shunts for life. Until recently, after-birth repair of the defect was the only treatment option. It may still be the only choice to repair some neural tube defects.

Surgery before birth: In the case of spina bifida the nerves are exposed to amniotic fluid within the uterine environment which can further damage the spinal cord. For this reason physicians studied the prenatal repair of NTD with the hope that it would improve postnatal outcomes.

This study, a randomized clinical trial, also known as the MOMs Trial, was able to show that fetal surgical repair of myelomeningocele (MMC) leads to decreased rates of hydrocephalus and improved leg function compared to the standard after-birth repair. However, the study also found complications that could occur in some fetuses that had fetal surgical repair, such as early birth, and rarely, death.

If you and your baby are both candidates for fetal surgery, you will meet with a group of fetal specialists who will discuss the risks and benefits of the procedure in detail to help you and your family decide the best treatment approach for you.

Fetoscopic surgical repair can lead to longer gestation, improved outcomes, lower rates of hydrocephalus, decreased need for shunts and improved leg function compared to after-birth repair. It may also preserve the mother’s ability to deliver vaginally following the initial repair and for all future subsequent births.

Texas Children's was one of the first centers to successfully perform open fetal surgery to treat spina bifida in 2011.The procedure has had good outcomes, but it also carries risks, including increased incidence of preterm birth, cesarean section and uterine rupture. Another option of prenatal repair is the fetoscopic method. Texas Children’s is one of the only centers in the U.S. that offers fetoscopic repair surgery for spina bifida. Read more about fetoscopic repair for spina bifida.

Another option, fetoscopic repair of spina bifida, is a minimally invasive surgery. Texas Children’s Fetal Center is one of the only centers in the U.S. that offers fetoscopic repair surgery for spina bifida.

Volumes and Outcomes

To learn more about our volumes and outcomes for spina bifida, please visit texaschildrens.org/neurosurgeryoutcomes.

Videos

To learn more about the Neurosurgery program at Texas Children’s Hospital and to inquire about admissions and patient candidates, please call 832-822-3950.