Newborn jaundice is common (60% term, 80% preterm). Risk-stratify by hour-of-life nomogram (AAP 2022) and risk factors. Direct/conjugated > 1 mg/dL or > 20% of total = always pathologic — biliary atresia must be excluded.
🚩 Red-flag clues (must not miss)
- •Jaundice in first 24 h of life = hemolysis or sepsis (always pathologic)
- •Direct (conjugated) hyperbili > 1 mg/dL or > 20% total = biliary atresia until proven otherwise
- •Total bili rising > 0.2 mg/dL/h = significant hemolysis
- •Acute bilirubin encephalopathy: lethargy, hypertonia, retrocollis, opisthotonus, high-pitched cry — risk of kernicterus
History
- Hour-of-life of bili measurement (essential for nomogram)
- Gestational age, birth weight, weight loss
- Feeding (breast vs formula, frequency, output)
- Maternal blood type, DAT, family hx of hemolysis (G6PD, spherocytosis)
Exam
- Cephalo-caudal progression of jaundice (face → trunk → extremities → soles)
- Hydration, weight loss > 10%
- Hepatosplenomegaly (hemolysis), petechiae
- Neuro: tone, suck, cry quality
Labs
- Total + direct bilirubin
- CBC + smear, retic count
- Blood type + Coombs (DAT)
- G6PD level (esp. Mediterranean, African, Asian descent)
- If direct bili ↑: LFTs, GGT, abdominal US, fractionated bili, sepsis w/u, TORCH
Differential & next step
| Diagnosis | Clue | Next step |
|---|---|---|
| Physiologic jaundice | After 24 h, peaks day 3–5 | Phototherapy if above threshold; reassess feeding |
| Breastfeeding jaundice (early) | Day 2–4, dehydration, weight loss | ↑ feeds q2–3h, lactation |
| Breast-milk jaundice (late) | Day 7–14, well infant, indirect | Continue BF; consider brief interruption if very high |
| Hemolysis — ABO/Rh | Mother O+, infant A or B; +DAT | Phototherapy; IVIG if rapidly rising |
| Hemolysis — G6PD | Family hx, ethnicity, low retic | Avoid oxidants |
| Sepsis / UTI | Lethargy, temp instability | Septic w/u, abx |
| Biliary atresia | Direct bili ↑, acholic stools, dark urine | URGENT US, HIDA, peds GI/surgery — Kasai before 8 wk |
| Hypothyroidism | Prolonged jaundice + lethargy + macroglossia | TSH, free T4 |
| Crigler-Najjar / Gilbert | Persistent indirect, no hemolysis | Genetic testing |
Medications & dosing
| Drug | Dose | Notes |
|---|---|---|
| Phototherapy | Per AAP 2022 nomogram (hour-of-life + risk) | Most common intervention; minimal side effects |
| IVIG | 0.5–1 g/kg IV over 2 h | For isoimmune hemolysis (ABO/Rh) when bili rising despite phototherapy |
| Exchange transfusion | Double-volume exchange | If bili at exchange threshold or signs of acute bilirubin encephalopathy |
Management / next steps
- Plot total bili on AAP 2022 hour-of-life nomogram with risk factors
- Phototherapy if at/above threshold — monitor q4–12h
- Adequate hydration (oral/IV) — do NOT routinely supplement breastfed infants with water
- Workup for direct hyperbili immediately (biliary atresia)
Newborn bilirubin calculator
Newborn Bili Calculator
AAP 2022 hour-of-life nomogram (approximation for teaching). Always confirm with the official AAP nomogram before treatment.
Phototherapy threshold
19 mg/dL
Exchange threshold
24 mg/dL
Below phototherapy threshold (19 mg/dL) — margin 9.0 mg/dL. Recheck per AAP follow-up table.
Pearls
- Use TOTAL bili (not subtracting direct) for phototherapy thresholds.
- Newborn bili calculator below uses AAP 2022 thresholds.
Source: https://fprmed.com/fprmedcom/Pages/Pedi/hyperbili.html
← Back to Pediatric DDx