All of the following are recognised maternal risk factors for TETRALOGY OF FALLOT EXCEPT:

Correct answer: A. Iron deficiency

• A. CORRECT — this is the exception. IRON DEFICIENCY causes maternal anaemia and is associated with low birth weight and preterm delivery, but it is NOT an established teratogenic risk factor for tetralogy of Fallot or other conotruncal cardiac malformations.
• B. MATERNAL DIABETES, particularly poorly controlled pregestational diabetes, substantially raises the risk of congenital heart disease including conotruncal defects such as tetralogy of Fallot and transposition of the great arteries.
• C. FOLIC ACID DEFICIENCY is a well-recognised risk factor for congenital malformations, including both neural tube and CARDIAC defects. Periconceptional folate supplementation reduces this risk, which is why it is recommended before conception.
• D. ALCOHOL is a proven cardiac teratogen. Fetal alcohol spectrum disorder includes septal defects and conotruncal anomalies alongside the midface hypoplasia, smooth philtrum, thin upper lip and short palpebral fissures.

Note: The four components of tetralogy: PULMONARY STENOSIS, VENTRICULAR SEPTAL DEFECT, OVERRIDING AORTA and RIGHT VENTRICULAR HYPERTROPHY. Dentally, expect cyanosis, clubbing, delayed eruption, enamel hypoplasia and a higher caries and periodontal disease burden. Determine the repair status and consult cardiology — unrepaired cyanotic disease, and repairs with residual defects near prosthetic material, remain in the highest-risk category for endocarditis prophylaxis.