If a pregnant patient uses anticonvulsants, how does spina bifida risk change?

• A. Increases
• B. Decreases
• C. No change
• D. Unknown

Answer: (A)

Exposure to anticonvulsants during early pregnancy raises the risk of neural tube defects, including spina bifida. Valproic acid carries the strongest association, and the risk increases with higher doses and when multiple anticonvulsants are used. Neural tube closure occurs in the first month of gestation, so disruption during that window can lead to defects. Many anticonvulsants interfere with folate metabolism, underscoring the rationale for folic acid supplementation before conception. If possible, use the lowest effective dose in monotherapy and consider switching to a safer agent before pregnancy; continue folate support. In short, the risk increases with anticonvulsant exposure, rather than decreasing, staying the same, or being unknown.