Do All Newborns Develop Jaundice?

Jaundice is an extremely common condition in newborns, affecting approximately 60% of term infants and up to 80% of preterm infants during the first week of life. It manifests as a yellowish discoloration of the skin and sclerae due to elevated serum bilirubin levels—primarily unconjugated (indirect) bilirubin.

This physiological jaundice arises from several interrelated factors unique to the neonatal period: increased red blood cell turnover, immature hepatic glucuronidation pathways that limit bilirubin conjugation, and enhanced enterohepatic circulation of bilirubin. In most cases, it peaks between days 3 and 5 of life and resolves spontaneously without intervention.

While jaundice is nearly ubiquitous in the early neonatal period, its presence is not universal—some infants never develop clinically apparent jaundice. Importantly, clinicians must distinguish benign physiological jaundice from pathological causes, such as hemolytic disease (e.g., Rh or ABO incompatibility), sepsis, metabolic disorders (e.g., G6PD deficiency), or congenital hypothyroidism. Red flags include onset within the first 24 hours, rapid bilirubin rise (>0.2 mg/dL/hour), total serum bilirubin exceeding age-specific phototherapy thresholds, or persistence beyond two weeks in term infants.

Routine bilirubin screening—especially in the first 72 hours—and adherence to evidence-based management guidelines help prevent kernicterus, a rare but devastating form of bilirubin-induced neurologic dysfunction. Thus, while jaundice is highly prevalent, vigilance and timely assessment remain essential components of newborn care.