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Open neural tube defects: Risk factors, prenatal screening and diagnosis, and pregnancy management

Stephanie Dukhovny, MD
Louise Wilkins-Haug, MD, PhD
Section Editors
Deborah Levine, MD
Lynn L Simpson, MD
Deputy Editor
Vanessa A Barss, MD, FACOG


Open neural tube defects (NTDs) are relatively common congenital anomalies that develop when a portion of the neural tube fails to close normally during the third and fourth weeks after conception (the fifth and sixth weeks of gestation). The resulting defect may involve the vertebrae, spinal cord, cranium, and/or brain. (See "Pathophysiology and clinical manifestations of myelomeningocele (spina bifida)", section on 'Embryology of the neural tube'.)

Two key advances related to open NTDs have occurred in recent decades:

Folic acid fortification of commonly consumed foods (eg, bread, flour, cornmeal, rice, pasta) and administration of folic acid supplements have been shown to prevent occurrence/recurrence of most open NTDs

Maternal serum and sonographic screening programs have led to identification of most affected pregnancies, allowing parents to make decisions about pregnancy management

This topic will review prenatal screening and diagnosis of open NTDs and other information of interest to obstetrical providers. Folic acid supplementation for prevention of open NTDs is discussed separately. (See "Folic acid supplementation in pregnancy".)

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Literature review current through: Nov 2017. | This topic last updated: Aug 29, 2017.
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