Moderate Hyperbilirubinemia Induces a Transient Alteration of Neonatal Behavior

Abstract

OBJECTIVE: To investigate the behavioral changes induced by moderate hyperbilirubinemia in the otherwise healthy, untreated newborn infant. METHODS: Fifty term neonates (23 boys) with untreated moderate hyperbilirubinemia (median: 14.3 mg/dL; range: 13.2-20 mg/dL) and 50 matched control subjects with lower bilirubin concentrations (median: 9.1 mg/dL; range: 5.3-12 mg/dL) were administered the Brazelton Neonatal Behavioral Scale at 87 hours of life (range: 72-110 hours). A subgroup analysis was also performed at 104 hours of life (range: 96-134 hours) and at 3 weeks of age. RESULTS: At the first examination, all behavioral clusters were significantly altered in the group with moderate hyperbilirubinemia. The visual and auditory capabilities of the hyperbilirubinemic infant were especially compromised. Although social-interactive cluster scores significantly correlated both with serum bilirubinemia and birth weight, the former accounted for 8.7% of the variance and the latter accounted for only 4.7%. The moderate hyperbilirubinemia neonates' scores also showed a negative correlation with the autonomic system and more frequent presence of tremors. After 24 hours, a decrease in serum bilirubin within the moderate hyperbilirubinemic group was associated with improved scores. At 3 weeks of age, the behavioral assessment of the 2 groups did not show significant differences. CONCLUSIONS: Untreated moderate hyperbilirubinemia is associated with a transient and apparently reversible alteration of neonatal behavior, particularly in the social-interactive area.