Red flags The following findings are of particular concern: Jaundice in the first day of life Total serum bilirubin > 18 mg / dL (> 308 micromol / L) Rate of rise of total serum bilirubin > 0.2 mg / dL / hour (> 3.4 micromol / L / hour) or > 5 mg / dL / day (> 86 micromol / L / day) Conjugated bilirubin concentration > 1 mg / dL (> 17 micromol / L) if total serum bilirubin is < 5 mg / dL (< 86 micromol / L) or > 20% of total serum bilirubin (suggests neonatal cholestasis) Jaundice after 2 weeks of age Lethargy, irritability, respiratory distress Interpretation of findings Evaluation should focus on distinguishing physiologic from pathologic jaundice.