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.
Table 3-1 lists several maternal and neonatal factors that increase the risk of developing severe hyperbilirubinemia among infants of 35 or more 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). The following factors (in order of decreasing importance) are associated with decreased risk of significant jaundice: total serum bilirubin (TSB) or transcutaneous bilirubin (TcB) level in the low-risk zone, gestational age greater than 41 weeks, exclusive bottle-feeding, black race, and discharge from the hospital after 72 hours.
Nomogram for designation of risk in 2840 well newborns of 36 or more weeks' gestational age with birth weight of 2000 g or more or 35 or more weeks' gestational age and birth weight of 2500 g or more 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.)
Table 3-1. Risk Factors for Development of Severe Hyperbilirubinemia in Infants of 35 or More Weeks' Gestation.a |Favorite Table|Download (.pdf)
Table 3-1. Risk Factors for Development of Severe Hyperbilirubinemia in Infants of 35 or More Weeks' Gestation.a
|Major Risk Factors|
|Predischarge TSB or TcB level in the high-risk zone (see Figure 3-1)|
|Jaundice observed in the first 24 h of life|
|Blood group incompatibility with positive direct antiglobulin test, other known hemolytic disease (eg, G6PD deficiency), elevated ETCO|
|Gestational age of 35-36 wk|
|Previous sibling who received phototherapy|
|Cephalohematoma or significant bruising|
|Exclusive breastfeeding, particularly if nursing is not going well and weight loss is excessive|
|East Asian race|
|Minor Risk Factors|
|Predischarge TSB or TcB level in the high intermediate-risk zone|
|Gestational age of 37-38 wk|
|Jaundice observed before discharge|
|Previous sibling with jaundice|
|Macrosomic infant of diabetic mother|
|Maternal age >25 y|
The three classifications of neonatal hyperbilirubinemia are based on the following mechanisms of accumulation: increased bilirubin load, decreased bilirubin conjugation, and impaired bilirubin excretion. In the newborn, unconjugated bilirubin is produced faster and removed more ...