Tetralogy of Fallot (ToF) — which of the following is NOT a risk factor for ToF?

Correct answer: D. Maternal folic acid supplementation (actually PROTECTIVE — not a risk factor)

• A. Maternal smoking during pregnancy is associated with increased risk of congenital heart defects.
• B. Maternal alcohol consumption is a recognized risk factor for congenital heart defects including ToF.
• C. Iron deficiency and anemia during pregnancy may be associated with some congenital heart defects.
• D. Correct. Folic acid supplementation is PROTECTIVE against neural tube defects and certain congenital heart defects — it is NOT a risk factor for Tetralogy of Fallot. Including it as an exception tests whether students know folic acid is beneficial. Risk factors for ToF include: maternal alcohol use, maternal smoking, maternal phenylketonuria, certain genetic syndromes (Down syndrome, DiGeorge syndrome).