Which maternal condition is listed as associated with spina bifida etiology?

• A. Maternal hyperthermia
• B. Maternal rubella
• C. Maternal anemia
• D. Maternal obesity

Answer: (A)

Elevated maternal temperature during early pregnancy can disrupt neurulation, the process that forms the neural tube. The neural tube closes in the first month of gestation, so a fever or exposure to high heat during this critical window can stress developing neural tissue, alter cell signaling, and increase cell death, leading to incomplete closure and spina bifida. This direct link to the timing of neural tube formation makes maternal hyperthermia the best answer.

Maternal rubella causes a different set of birth defects (congenital rubella syndrome) rather than neural tube defects. Anemia is not a classic teratogen for neural tube defects, and while obesity can be a risk factor for some complications, hyperthermia has the strongest established association with spina bifida among these options.