newborn Blood Spot Screening
A heel-prick blood test performed in the first week of life to detect rare but serious genetic, metabolic, and blood disorders.
| Timing | Day 5 after birth (ideal) |
| Method | heel prick, 4 blood spots collected |
| Conditions screened | 9 (England), varies by UK nation |
| Detection rate | ~1,000 babies/year (UK) |
Conditions Detected
The UK screening programme tests for nine conditions:
| Condition | Prevalence | Key Risk |
|---|---|---|
| Sickle cell disease | 1 in 2,000 | Severe pain, infections, organ damage |
| Cystic fibrosis | 1 in 2,500 | Lung/digestive complications |
| Congenital hypothyroidism | 1 in 3,000 | Severe developmental delay |
| Phenylketonuria (PKU) | 1 in 10,000 | Brain damage from protein buildup |
| Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) | 1 in 10,000 | Life-threatening metabolic crisis |
| Maple syrup urine disease (MSUD) | 1 in 185,000 | Brain damage from amino acid buildup |
| Isovaleric acidaemia (IVA) | 1 in 100,000 | Metabolic crisis, developmental delay |
| Glutaric aciduria type 1 (GA1) | 1 in 100,000 | Brain damage during illness |
| Homocystinuria (HCU) | 1 in 100,000 | Blood clots, eye/bone problems |
The Test Process
- Collection — Midwife or nurse pricks baby's heel, collects 4 blood spots on card
- Timing — Day 5 ideal (allows PKU to show); acceptable days 0–8
- Processing — Card sent to laboratory, results within 6–8 weeks
- Follow-up — Only contacted if abnormal result or repeat needed
Results
Normal result: No contact (some areas send letter) Abnormal result: Phone call within days, referral to specialist Inconclusive result: Repeat test requested (common, usually not concerning)
Importance of Early Detection
PKU example: Without dietary modification from birth, protein from breast milk/formula causes immediate brain damage. With early detection and low-protein diet, severe intellectual disability and death are preventable.
Similar urgency applies to other conditions—early intervention significantly improves outcomes for all nine disorders.
Parental Consent
Testing is routine but not compulsory. Parents may decline, though medical professionals strongly recommend the screening due to serious consequences of missed diagnoses.
See also: Newborn Physical Examination, Newborn Hearing Screening, Phenylketonuria, Cystic Fibrosis, Sickle Cell Disease