Input
Bhutani Nomogram (approximate)
Colored bands represent approximate 40th (green), 75th (blue), and 95th (red) percentile TSB curves by postnatal hour. Your data point appears as a black dot.
40th
75th
95th
Your point
Result
Tool scope & caution
Applies to well infants ≥35 weeks with no prior phototherapy. The visualized curves are approximate for training. Always confirm management using approved guideline calculators (e.g., phototherapy thresholds) and local policy.
- If TcB is high/intermediate: obtain serum TSB.
- Risk zones estimate probability of future bilirubin ≥95th percentile.
- Risk zones do not equal treatment thresholds.
FAQs
The chart stratifies bilirubin percentiles by postnatal hour. High (≥95th), high‑intermediate (75th–95th),
low‑intermediate (40th–75th), and low (<40th) zones estimate the chance that a later value will exceed the 95th percentile. They are not treatment thresholds.
No. Phototherapy and exchange thresholds require guideline calculators that factor gestational age and neurotoxicity risks.
Use trusted clinical tools for management decisions and confirm with serum testing when indicated.
The original risk zones were developed for well infants ≥35 weeks. For earlier gestations or ill infants, the probability model differs,
and separate guidance applies.
No. TcB is a screening estimate and may differ from TSB, especially at higher values or after phototherapy. If the TcB falls in a higher zone,
confirm with a serum measurement.
No. They are smoothed, approximate representations created for education and software demonstration. Always use authoritative tools for patient care.
Enter age in completed hours since birth (e.g., 36 means 36 hours old). For infants older than 120 hours, interpretive accuracy decreases for this model.
Review recognized neonatal jaundice guidelines and education pages. Pair this visualization with institutional pathways and validated calculators.
Disclaimer
This educational utility provides an approximate visualization of Bhutani risk zones. It is NOT a substitute for clinical judgment,
institutional policy, or recognized calculators for treatment thresholds. If an infant appears unwell or bilirubin is rising rapidly,
seek urgent evaluation.