Newborn screening is drawn after at least how many hours of life?

• A. 12 hours
• B. 6 hours
• C. 24 hours
• D. 48 hours

Answer: (C)

The timing of newborn screening is about getting reliable results by letting metabolic markers stabilize after birth. In the first hours, rapid changes in physiology and feeding, plus maternal influences, can skew the test results. Waiting at least 24 hours allows these markers to reach detectable, stable levels, reducing false positives or negatives. While many programs also accept collection up to 48 hours for even more accuracy, the minimum time to ensure a dependable screen is 24 hours. If screening occurs earlier than that, a repeat test is commonly required to confirm results.