Which of the following factors increases the risk of spina bifida?

• A. Increased folic acid intake
• B. Maternal age under 20
• C. Folic acid deficiency
• D. Regular exercise

Answer: (C)

Spina bifida is a neural tube defect that happens when the neural tube doesn’t close early in pregnancy. Folate is essential for rapid cell division and DNA synthesis during that exact time window, so having enough folate around conception and in the first weeks of gestation helps the neural tube close properly. When folic acid is deficient, the risk of neural tube closure failure increases, leading to spina bifida. That’s why this factor is the one that raises risk among the options.

Increasing folic acid intake is protective, not a risk, so it wouldn’t increase risk. Maternal age under 20 isn’t a well-established risk factor for spina bifida, and regular exercise doesn’t have a clear impact on neural tube closure.