Kernicterus in Late Preterm Infants Cared for as Term Healthy Infants

Objective

To compare the clinical profile and health care experiences related to management of newborn jaundice and hyperbilirubinemia in preterm infants (<37^0/7 weeks gestation) who are cared for as term infants (≥37^0/7 weeks) and develop acute and/or chronic posticteric sequelae.

Methods

Retrospective study of a convenient sample of term and near term infants voluntarily reported to the Pilot Kernicterus Registry (1992-2003). Study infants were required to meet the clinical definitions for acute bilirubin encephalopathy (moderate or advanced severity) and/or the classical signs of kernicterus. Main outcome measures were the comparison of etiology, severity and duration of extreme hyperbilirubinemia (TSB levels >20 mg/dL), response to interventions of intensive phototherapy and exchange transfusion, and health care delivery experiences in preterm as compared with term infants.

Results

No targeted attention was accorded to preterm infants during their neonatal health care experiences as related to predischarge risk assessment, feeding, discharge follow-up instructions, or breastfeeding, regardless of the known vulnerability of preterm infants to safely transition during the first week after birth. The TSB levels, age at re-hospitalization, and birth weight distribution were similar for late preterm and term infants. Large for gestational age and late preterm infants disproportionately developed kernicterus as compared with those who were appropriate for gestational age and term. Clinical management of extreme of hyperbilirubinemia, by the attending clinical providers, was not impacted or influenced by the gestational age, clinical signs, or risk assessment. This resulted in severe posticteric sequelae which was more severe and frequent in late preterm infants.

Conclusions

Late prematurity (34^0/7 to 36^6/7 weeks) of healthy infants was not recognized as a risk factor for hazardous hyperbilirubinemia by clinical practitioners. Unsuccessful lactation experience was the most frequent experience; being large for gestational age as well as the other known biologic risk factors for hyperbilirubinemia and bilirubin neurotoxicity were not identified by the clinical care providers either before discharge or at immediate postdischarge follow up.

Keywords:  neonatal hyperbilirubinemia , jaundice , kernicterus , prematurity , near-term , late preterm