Newborn jaundice interpretation
Newborn bilirubin nomogram guide
Understand what newborn bilirubin nomograms and Bhutani risk-zone language mean, and when to move from historical risk context to current AAP 2022 treatment thresholds.
Last reviewed: 2026-04-28
Quick answer
Current management uses thresholds
Nomogram terms, translated
| Term | What it means | Current use |
|---|---|---|
| Age in hours | The x-axis for classic newborn bilirubin nomograms. A bilirubin level cannot be interpreted safely without the sampling age. | Still essential for AAP 2022 thresholds. |
| Bilirubin percentile or risk zone | Historical Bhutani-style language estimates the chance of a later bilirubin level above the 95th percentile. | Useful for reading old notes, but not the current treatment decision axis. |
| Phototherapy threshold | A treatment line, not the same thing as a percentile-risk zone. | Use current AAP 2022 gestational-age and risk-factor curves. |
| High-risk zone | A signal for closer follow-up or repeat bilirubin in older nomogram language. | Reframe as current bilirubin value relative to the AAP 2022 phototherapy threshold. |
| Delta from phototherapy | The bilirubin value's distance below or above the treatment threshold. | This is the current AAP 2022 follow-up anchor after discharge. |
Safe workflow
- Confirm exact postnatal age in hours at the sample.
- Confirm bilirubin source: TSB for treatment decisions, TcB for screening when appropriate.
- Check gestational age and neurotoxicity risk factors.
- If an old note uses risk-zone language, treat it as historical context.
- Use the current AAP 2022 bilirubin calculator for phototherapy, escalation, exchange, and follow-up decisions.
Nomogram vs current threshold workflow
Use nomogram language
- Teaching why age in hours changes bilirubin interpretation.
- Reading older newborn nursery notes that mention Bhutani risk zones.
- Explaining why a single bilirubin number is incomplete without timing.
Use AAP 2022 thresholds
- Deciding whether phototherapy is indicated.
- Planning repeat bilirubin timing after discharge.
- Escalating care near exchange transfusion thresholds.
Open the current calculator
For a current treatment or follow-up decision, calculate with AAP 2022 thresholds and document the distance from the phototherapy and exchange thresholds.
See how to use the bilirubin calculator if you need input-by-input workflow help.
Related bilirubin tools
- Newborn bilirubin calculator - run current AAP 2022 treatment thresholds.
- Bilirubin 2004 vs 2022 guidelines - compare older risk-zone language with the current workflow.
- Neonatal and newborn calculators - open related newborn tools.
References
FAQs
A newborn bilirubin nomogram plots bilirubin by postnatal age in hours so a value can be interpreted in time context. Older Bhutani-style nomograms described risk zones for later significant hyperbilirubinemia.
No. A risk nomogram estimates risk or percentile context, while a phototherapy threshold chart tells you when treatment is indicated for a specific age, gestational age, and risk-factor state.
For current AAP 2022 care, follow-up is based on how far the bilirubin value is from the phototherapy threshold. Use Bhutani-style risk zones mainly for historical notes or teaching.
Bilirubin changes rapidly in the first days after birth. A value that is concerning at 18 hours may be less concerning later, and the reverse can happen depending on gestational age, trend, and risk factors.
Document that the term came from a historical nomogram, then recalculate current phototherapy and exchange thresholds using exact age in hours, gestational age, bilirubin source, and neurotoxicity risk factors.