When is the recommended timing for a newborn genetic screening?

Newborn genetic screening is ideally recommended to be performed after 24 hours of life. This timing is necessary for a couple of important reasons.

First, many metabolic disorders detected through screening, such as phenylketonuria (PKU) or congenital hypothyroidism, may not show abnormalities in tests conducted too early. This delay allows sufficient time for metabolites or hormone levels to stabilize, ensuring accurate results.

Second, there are specific instructions from health authorities, such as the American Academy of Pediatrics and the Centers for Disease Control and Prevention, endorsing screening typically within the first few days of life. Often, this occurs after the baby has begun feeding, which is generally after 24 hours, as appropriate nutrition is necessary for reliable testing.

While screening at birth, before discharge, or soon after may seem reasonable, the accurate timing that promotes effective early detection of potential genetic conditions aligns with the recommendation to perform the screening after the baby is at least 24 hours old.