Question

Assertion (A): All newborns should be screened for hypothyroidism at birth.

Reason (R): Treatment at birth for hypothyroidism can assure normal mental development.

• A. Both A and R are true and R is the correct explanation of A.
• B. Both A and R are true but R is NOT the correct explanation of A.
• C. A is true but R is false.
• D. A is false but R is true.

Hint:

Congenital hypothyroidism looks normal at birth but causes irreversible brain damage if treatment is delayed.

Answer 1

The Correct Option is A

This question links newborn thyroid screening to the actual benefit that screening is meant to deliver.

1. Assertion: Screening every newborn for hypothyroidism is a standard part of newborn care, because a baby with this condition looks normal at birth and cannot be picked up by a simple physical exam alone. This makes the assertion true.
2. Reason: Thyroid hormone drives brain growth in the first weeks of life. Giving replacement hormone early, ideally within the first month, prevents the intellectual disability that would otherwise follow. This is also a true and well-established fact.

Screening exists precisely because early treatment protects the brain, so the reason is not just true on its own, it is the actual justification for the assertion.

Let's summarize:

• Congenital hypothyroidism is clinically silent at birth.
• A heel-prick TSH test catches it before symptoms appear.
• Starting treatment early prevents permanent mental impairment, which is exactly why screening is recommended.

So the final answer is: both A and R are true, and R is the correct explanation of A.