Spina bifida is a condition that occurs when a developing baby’s spine and spinal cord don't form properly. It is congenital (present at birth) and affects the baby’s neural tube, which eventually develops into the spinal cord.

In a normal pregnancy, the neural tube forms early and closes within 28 days of conception. But in babies with spina bifida, the neural tube fails to close correctly, which can lead to defects in the bones of the spine and the central nervous system. Depending on the severity of the defect, a child may have physical disabilities ranging from minor to significant.

Types of Spina Bifida

There are several types of spina bifida; symptoms vary by type and can be different for every individual.

Spina Bifida Occulta

The mildest type, occulta usually does not involve the spinal nerve and has no symptoms. People with this type rarely know they have spina bifida unless it is found on an exam or lab test. Because there is skin covering the defect in the spine, this is also called a closed neural tube defect.

Spina Bifida Meningocele

The membranes surrounding the spinal cord protrude through the bones of the spine and form a fluid-filled sac, but the spinal cord is not affected. Nerve damage is uncommon.

Spina Bifida Myelomeningocele

This is the most severe type, in which the spinal canal remains open along several vertebrae. Both the membranes and spinal cord nerves protrude and are exposed, forming a bump on the baby’s back. Meningoceles and myelomeningoceles do not have skin covering the defect, and these abnormalities are called open neural tube defects.

Risk Factors for Spina Bifida

Though the causes of spina bifida aren't known, there are known risk factors including:

Folic Acid Deficiency

Folic acid, the synthetic form of folate or vitamin B-9, can significantly reduce the risk of having a baby with neural tube defects. Women who are planning to become pregnant should begin taking 400 micrograms of folic acid supplements daily at least one month before conception and continue throughout their pregnancy.

Family History of Neural Tube Defects

Women who were born with a neural tube defect, or who have previously had children with neural tube defects, have a greater chance of having a child with the defect. Still, most babies with spina bifida have no known family history of neural tube defects.


Some medications taken during pregnancy can interfere with folic acid absorption and may increase the risk of neural tube defects.


Women with uncontrolled diabetes may have a greater risk of having a baby with spina bifida.

If you are pregnant or planning to become pregnant and have risk factors for spina bifida, your Mercy physician can let you know if you need to make any changes or take other precautions.

Diagnosing & Treating Spina Bifida

Prenatal testing, including blood tests, ultrasound exams and amniocentesis, can screen for spina bifida during pregnancy. If we find your baby has spina bifida, Mercy’s maternal and fetal medicine specialists will talk with you and your family about your baby’s neural tube defect, how we plan to treat it, and what you can expect in the days ahead.

Treatment will depend on the type and severity of the condition. Spina bifida occulta usually needs no special treatment. More severe types may require surgery shortly after birth.

In some cases, fetal surgery may be an option to repair the baby’s spinal cord while the baby is still in the uterus. Your Mercy team of maternal and fetal medicine specialists, along with our collaborative team of pediatric neurosurgeons and fetal surgeons, will counsel you on the best options for your baby.

Learning that your baby may have spina bifida can cause a great deal of anxiety and fear, but most babies born with this condition have treatable symptoms and bright futures. Count on Mercy for heartfelt support and loving guidance through this challenging time.

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