ESSENTIALS OF DIAGNOSIS
Visible yellowing of the skin, ocular sclera, or both are present in neonatal jaundice; however, because visual estimates of total bilirubin are prone to error, quantitative testing (serum or transcutaneous) should be completed in infants noted to be jaundiced within the first 24 hours of life.
Risk of subsequent hyperbilirubinemia can be assessed by plotting serum bilirubin levels onto a nomogram; all bilirubin levels should be interpreted according to the infant’s age (in hours).
Nearly every infant is born with a serum bilirubin level higher than that of the normal adult. Approximately 60% of newborns are visibly jaundiced during the first week of life. The diagnostic and therapeutic challenge for the physician is to differentiate normal physiologic jaundice from pathologic jaundice, and to institute appropriate evaluation and therapy when necessary.
Several factors are considered as major predictors for the development of severe hyperbilirubinemia among infants of ≥35 weeks’ gestation. Among the most significant clinical characteristics associated with severe hyperbilirubinemia are predischarge levels in the high-risk zone on the serum bilirubin nomogram (Figure 3-1) and jaundice noted within 24 hours of birth. Other risk factors include various forms of hemolytic disease [eg, ABO incompatibility, glucose-6-phosphate dehydrogenase (G6PD) deficiency], elevated end-tidal carbon monoxide, gestation age of 35–36 weeks, a sibling who required phototherapy, cephalohematoma or significant bruising, exclusive breastfeeding, East Asian race, maternal age ≥25 years, and male gender.
Nomogram for designation of risk in 2840 well newborns of ≥36 weeks’ gestational age with birth weight of ≥2000 g or ≥35 weeks’ gestational age and birth weight of ≥2500 g based on the hour-specific serum bilirubin value. (Reproduced with permission from American Academy of Pediatrics Subcommittee on Hyperbilirubinemia. Management of hyperbilirubinemia in the newborn infant 35 or more weeks of gestation. Pediatrics. 2004;114:297.)
While the American Academy of Pediatrics currently recommends universal predischarge bilirubin screening using total serum bilirubin (TSB) or total cutaneous bilirubin (TcB) measurements, the United States Preventive Services Task Force (USPSTF) determined that the evidence is insufficient to recommend screening infants for hyperbilirubinemia to prevent chronic bilirubin encephalopathy; the American Academy of Family Physicians concurs with the USPSTF position. In clinical practice, however, testing is completed for the vast majority of infants.
American Academy of Pediatrics Subcommittee on Hyper-bilirubinemia. Management of hyperbilirubinemia in the newborn infant 35 or more weeks of gestation. Pediatrics.
[PubMed: [PMID: 15231951]]
US Preventive Services Task Force. Screening of infants for hyperbilirubinemia to prevent chronic bilirubin encephalopathy: US preventive services task force recommendation statement. Pediatrics.
[PubMed: [PMID: 20704172]]
The three classifications of neonatal hyperbilirubinemia are based on the following mechanisms of accumulation: increased ...