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:

Ask why screening is done before symptoms appear, not after.

Answer 1

The Correct Option is A

Step 1: Understand the assertion.
Congenital hypothyroidism (low thyroid hormone from birth) is one of the most common preventable causes of intellectual disability in children. Because affected babies usually look normal at birth and show no obvious symptoms in the first weeks, the condition is easy to miss on a routine physical check alone. This is why universal screening of all newborns, usually a heel-prick blood test for TSH or T4 done in the first few days of life, is recommended everywhere it is feasible. So the assertion is true.

Step 2: Understand the reason.
Thyroid hormone is essential for normal brain growth in the first weeks and months of life. If congenital hypothyroidism is picked up through screening and treatment with levothyroxine is started promptly, close to birth, the child's brain development proceeds normally and long-term intellectual disability is largely prevented. If treatment is delayed, the damage becomes permanent. So the reason is also true.

Step 3: Check if the reason explains the assertion.
The whole point of screening every newborn is to catch the condition before symptoms appear, so that treatment can start early enough to protect brain development. In other words, screening is worthwhile precisely because early treatment prevents mental retardation. This means R is a correct, direct explanation of why A is recommended.

Step 4: Rule out the other options.
Option (b) does not fit, since the two statements are not just coincidentally true, one is the reason for the other. Option (c) fails because R is true. Option (d) fails because A, the recommendation for universal screening, is also true.

Final Answer:
Both A and R are true and R is the correct explanation of A.