Which statement about spina bifida risk factors is most accurate?

• A. It is caused only by prenatal exposure
• B. There is no genetic component
• C. Genetics and environmental factors can influence risk
• D. It occurs spontaneously with no risk in future pregnancies

Answer: (C)

Spina bifida risk is multifactorial, shaped by both genetic predisposition and environmental influences. There is evidence of a genetic component—familial clustering and population differences show heritable susceptibility—yet environmental factors also play a crucial role, such as maternal folate status, diabetes, obesity, and certain medications around conception. Because of this blend, risk in future pregnancies is not zero, especially if there is already an affected child or other risk factors.

The other statements are limited or incorrect: risk is not caused solely by prenatal exposure, there is indeed a genetic component, and there is some recurrence risk in future pregnancies rather than no risk at all. The most accurate view is that genetics and environmental factors together influence risk.