Which statement about newborn screening timing is correct?

Which statement about newborn screening timing is correct?

• A. It must be performed after 24 hours and within 3 days
• B. It must be performed before birth
• C. It must be performed within the first hour after birth
• D. It is optional

Answer: (A)

Timing matters in newborn screening because the markers used to detect conditions need time to reach detectable levels, and early samples can be distorted by maternal hormones and feeding. Collecting the sample after about 24 hours of life allows these markers to stabilize and improves accuracy, while still enabling timely follow-up. Giving the test within the first 72 hours (up to about 3 days) keeps results relevant for early intervention and fits typical hospital workflows. Sampling before birth isn’t how this program works, since it relies on a newborn blood spot after birth. And in most systems, this screening isn’t optional but a standard public health measure.

Timing matters in newborn screening because the markers used to detect conditions need time to reach detectable levels, and early samples can be distorted by maternal hormones and feeding. Collecting the sample after about 24 hours of life allows these markers to stabilize and improves accuracy, while still enabling timely follow-up. Giving the test within the first 72 hours (up to about 3 days) keeps results relevant for early intervention and fits typical hospital workflows. Sampling before birth isn’t how this program works, since it relies on a newborn blood spot after birth. And in most systems, this screening isn’t optional but a standard public health measure.