What is Spina Bifida and Screening Procedures During Pregnancy

July 11, 2018

An Overview of Spina Bifida

Spina bifida is a birth defect that is classified as a neural tube defect. It occurs when the bones of the spine and the nerve membranes surrounding the spine do not form properly.  Spina bifida can range from mild to severe. The location, size and nerve involvement of the spinal defect has a direct correlation to the severity of spina bifida. Most cases of spina bifida are generally mild and do not require intervention.  More severe cases may require surgical intervention after the baby is born.


The exact cause of spina bifida is unknown;  however, there is evidence to suggest that genetic as well as environmental components may be contributing factors for spina bifida. People who have a family history of spina bifida are at increased risk for the condition.

Risk factors that may increase the risk to a pregnancy to have spina bifida include ethnicity, gender, nutrition, maternal factors, and medication use in pregnancy.  Spina bifida is more common among Hispanic and Caucasian groups. Girls are more likely to be born with this birth defect, and women who have a folate deficiency are more likely to deliver a baby with spina bifida. Certain medications, like an anti-seizure medication called valproic acid, may increase the risk for a pregnancy to have spina bifida. Discussion with your obstetrician and physician is important to determine the best or most effective medication or dose to balance management of maternal seizures and safety for the pregnancy.

Folate is a nutrient that is essential for the development of the neural tube.  It is recommended to take folic acid before and during pregnancy to prevent spina bifida. The synthetic form of folic acid is folate and can be taken as a multivitamin.  Additionally, obesity and diabetes can increase the risk of spina bifida.



It is recommended to have a blood screen and ultrasound performed during pregnancy to rule out spina bifida.  The blood screen known as maternal serum alpha-fetoprotein (AFP) test can be used to screen for spina bifida. This protein is produced by the developing baby’s liver. If the AFP levels are high, this can suggest that baby has a neural tube defect or may have AFP leaking out of the spinal opening.

A diagnostic ultrasound can be performed through an accredited facility to diagnose and determine severity of the defect. The sonographer performing the exam will visualize the brain and spine in detail in addition to other parts of the baby.

Furthermore, an amniocentesis can be performed after 16 weeks gestation in the pregnancy. This procedure involves taking a small sample from the amniotic fluid. It can also detect abnormally high AFP levels. This test is associated with a slightly increased risk of miscarriage of about 1 in 1000 procedures. This risk number is dependent upon the office in which the procedure is performed.


Preventing Spina Bifida

Proper nutrition before and during pregnancy can reduce the risk of spina bifida. It is suggested to take 400mcg of folic acid per day before and during pregnancy.  Folic acid can be taken as a multivitamin that can be administered by an obstetrician.  Other benefits to folic acid include prevention of congenital heart defects or cleft palate and cleft lip. Folate and folic acid can also be found in certain foods like egg yolk, citrus fruits, beans and dark green vegetables.

An increased amount of folic acid may be required if you have previously given birth to a baby with spina bifida, are diabetic or take certain anti-seizure medications. It is recommended to consult with your physician prior to pregnancy in order to review medical history and allow the doctor to help facilitate a healthy, successful pregnancy.