What are signs of newborn jaundice that require evaluation?

Neonatal jaundice (hyperbilirubinemia) is common — 60% of full-term and 80% of preterm infants develop visible jaundice. Most cases are physiologic and benign. Pathologic jaundice (warrants evaluation): (1) Onset in first 24 hours of life — suggests hemolysis, sepsis, or other serious cause; (2) Rapidly rising bilirubin (>5 mg/dL/day); (3) Total bilirubin >15 mg/dL in full-term infants (>10 in preterm); (4) Jaundice persisting >2 weeks in full-term, >3 weeks in preterm; (5) Direct (conjugated) bilirubin >2 mg/dL — suggests biliary obstruction or hepatocellular disease; (6) Associated signs: poor feeding, lethargy, irritability, hypotonia, fever, vomiting; (7) Family history of jaundice. Severe untreated jaundice can cause kernicterus — irreversible neurological damage from bilirubin crossing into the brain. Risk factors: prematurity, breastfeeding (more common but typically benign), ABO or Rh incompatibility, hereditary hemolytic disorders (G6PD deficiency, sickle cell), birth trauma with bruising. Assessment: visual inspection (jaundice typically progresses cephalocaudal); serum bilirubin levels; transcutaneous bilirubinometer for screening. Treatment: phototherapy (specific wavelength of light converts bilirubin to excretable form) for moderate levels; exchange transfusion for very high levels or signs of kernicterus. Breastfeeding jaundice: continue breastfeeding, ensure adequate intake. Discharge teaching: parents should observe for worsening jaundice and seek evaluation if concerning.