TERATOGENS

Question 1

What is the teratogenic effect of Valproic Acid?

Answer 1

Neural Tube Defect

Rationale / Concept:
Valproic acid interferes with folate metabolism, which is essential for proper neural tube closure in early embryogenesis.

Question 2

What is the teratogenic effect of ACE Inhibitors?

Answer 2

Renal dysgenesis, oligohydramnios

Rationale / Concept:
ACE inhibitors block angiotensin II, which is important for fetal renal blood flow → impaired kidney development → low amniotic fluid (oligohydramnios).

Question 3

What is the teratogenic effect of Diethylstilbestrol (DES)?

Answer 3

Vaginal adenocarcinoma

Rationale / Concept:
DES is a synthetic estrogen; in utero exposure alters vaginal epithelium differentiation, predisposing to malignancy in female offspring.

Question 4

What is the teratogenic effect of Isotretinoin?

Answer 4

Heart and brain anomalies

Question 5

What is the teratogenic effect of Lithium?

Answer 5

Ebstein’s anomaly

Question 6

What is the teratogenic effect of Methimazole?

Answer 6

Aplasia cutis

Rationale / Concept:
Methimazole inhibits thyroid hormone synthesis in the fetus → abnormal skin and scalp development (localized absence of skin).

Question 7

What is the teratogenic effect of Phenytoin?

Answer 7

Cleft lip & palate, cryptorchidism

Question 8

What is the teratogenic effect of Streptomycin?

Answer 8

8th cranial nerve damage (hearing loss)

Rationale / Concept: Aminoglycosides cross the placenta → ototoxicity in developing fetal inner ear.

Question 9

What is the teratogenic effect of Tetracycline?

Answer 9

Altered bone growth

Rationale / Concept:
Tetracycline binds calcium in bones and teeth → impairs ossification and causes discoloration.

Question 10

What is the teratogenic effect of Warfarin?

Answer 10

Hypoplastic nose and frontal bossing

Rationale / Concept:
Warfarin inhibits vitamin K-dependent clotting factors → disrupts cartilage and bone formation in the fetal face and skull.

Question 11

What is the teratogenic effect of Thalidomide (S-enantiomer)?

Answer 11

Phocomelia (shortened limbs)

Rationale / Concept:
Thalidomide inhibits angiogenesis during limb bud development, resulting in severely shortened or absent limbs.

Question 12

What is the teratogenic effect of Ethanol?

Answer 12

Smooth philtrum, clinodactyly

Question 13

Isotretinoin teratogenic effect

Answer 13

Heart and Brain Anomaly