Which drug-teratogenic pairing is correctly matched?

Which drug-teratogenic pairing is correctly matched?

• A. Valproic Acid: genital tract malformation
• B. Lithium: abnormal tricuspid valve
• C. Methimazole: neural tube defect
• D. Alcohol: macrocephaly

Answer: (B)

Exposure to lithium during early pregnancy is classically linked to Ebstein's anomaly, a defect of the tricuspid valve where the leaflets are displaced toward the apex, leading to abnormal structure and function of the right side of the heart. This makes the pairing with an abnormal tricuspid valve the correct match. Valproic acid, by contrast, is best known for increasing the risk of neural tube defects such as spina bifida and anencephaly, not genital tract malformations. Methimazole in early pregnancy is associated with embryopathy including scalp defects (aplasia cutis) and other anomalies rather than neural tube defects. Alcohol exposure commonly causes fetal alcohol spectrum disorders, with features like microcephaly rather than macrocephaly.

Exposure to lithium during early pregnancy is classically linked to Ebstein's anomaly, a defect of the tricuspid valve where the leaflets are displaced toward the apex, leading to abnormal structure and function of the right side of the heart. This makes the pairing with an abnormal tricuspid valve the correct match.

Valproic acid, by contrast, is best known for increasing the risk of neural tube defects such as spina bifida and anencephaly, not genital tract malformations. Methimazole in early pregnancy is associated with embryopathy including scalp defects (aplasia cutis) and other anomalies rather than neural tube defects. Alcohol exposure commonly causes fetal alcohol spectrum disorders, with features like microcephaly rather than macrocephaly.