newborn Blood Screening

Routine heel-prick test performed within 48–72 hours of birth to detect metabolic, genetic, and endocrine disorders.

Purpose

Newborn blood screening detects conditions that:

• Cause no immediate symptoms at birth
• Lead to severe complications (intellectual disability, organ damage, death) if untreated
• Are manageable with early intervention (dietary changes, medication, enzyme replacement)

Without screening, brain damage or death can occur before symptoms appear, particularly with metabolic disorders requiring immediate dietary modification.

Conditions Detected

Number of conditions tested varies by location. California tests for 61 disorders; other regions test for fewer.

Common categories:

• Metabolic disorders — Inability to digest specific proteins or produce enzymes
• Endocrine disorders — Hormone deficiencies
• Haemoglobin disorders — Sickle cell disease, thalassaemia
• Cystic fibrosis — Mucus production disorder

Phenylketonuria (PKU) Example

PKU illustrates why early detection matters:

With detection at birth and dietary modification, negative consequences are entirely avoidable. Without testing, diagnosis comes too late to prevent brain damage.

Procedure

1. Heel prick — Small blood sample collected from baby's heel
2. Laboratory analysis — Blood tested for multiple conditions simultaneously
3. Results — Typically within 1–2 weeks; urgent results communicated immediately

Follow-Up

If screening indicates potential condition:

• Further diagnostic testing required (initial screening shows risk, not diagnosis)
• Specialist referral arranged
• Treatment plan initiated immediately if confirmed

See also: PKU, Cystic Fibrosis, [[Newborn Hearing Screening]], Metabolic Disorders, Heel Prick Test