[Physiologic levels of bilirubin and behavior in healty infants during the neonatal period].

The purpose of this study was to evaluate behavioral differences in healthy newborns in relationship to bilirubin serum levels within the normal physiological range. Seventy-three healthy full-term newborns of adequate weight for their gestational age had bilirubin levels measured in a blood sample obtained by heel puncture on the third day of life. The Brazelton Neonatal Behavioral Assessment Scale (NBAS, 1984 version) was administered between the 60th and 80th hours of life. Results showed a mean bilirubin value of 123.12 mumol/L (7.2 mg/dL). There was an inverse correlation between serum bilirubin levels and behavior in regards to habituation, orientation, motor maturity and interaction of the NBAS. Although it can not be concluded that physiological bilirubin levels cause significant neurological disturbances, these results suggest that newborns with higher physiological bilirubin levels have some difficulties interacting with their caretakers.