This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
What is the best time to screen for neonatal hypothyroidism 
Select and explain. 
A. 1 - 2 days after birth, B. 2 - 4 days after birth, C. 1 - 2 has after birth, D. 2 - 4  has after birth
B: 2 - 4 days after birth
Answer: B: 2 - 4 days after birth 
Explanation: At birth, due to stress TSH level increases till 3 days(72 hours) , By 72 days ⇒ TSH becomes normal. Hence best time to screen is after 3 days i.e 2 - 4 days after birth.