Neonatal jaundice at birth or before 24 hours is commonly due to:

Jaundice occurring before age 24 hours is generally considered "pathologic" and requires further evaluation. Although some healthy infants appear slightly jaundiced by 24 hours, the presence of jaundice before 24 hours requires (at least) a serum bilirubin measurement. If indicated, further evaluation for possible hemolytic disease or other diseases should be done. Phototherapy and/or exchange transfusion may be indicated for rapidly rising TSB levels in the first 24 hours of life. Jaundice within 24 hour of life is due to erythroblastosis fetalis until proved otherwise.