KERNICTERUS IN PREMATURE-INFANTS - CURRENT PREVALENCE AND RELATIONSHIP TO NICHD PHOTOTHERAPY STUDY EXCHANGE CRITERIA

Objective. This study was undertaken to determine the current prevalen ce of kernicterus in premature neonates and to relate the occurrence o f kernicterus to 1) the categorization of the infant as ''at risk'' by National Institute of Child Health and Human Development (NICHD) Phot otherapy Study exchange transfusion criteria, and 2) the clinical mana gement of the infant's hyperbilirubinemia. Design. Retrospective revie w of postmortem and clinical records. Setting. Magee-Womens Hospital, a University of Pittsburgh Medical Center affiliated hospital with app roximately 10 000 deliveries per year and a Level III Neonatal Intensi ve Care Unit with about 1400 admissions annually. Subjects. All neonat es autopsied between January I, 1984 and June 30, 1993 who were < 34 w eeks gestation and who lived at least 48 hours; a total of 81 infants. Results. Three infants had kernicterus resulting in a prevalence rate of 4%. These cases included: 1) a 33-week newborn with nonimmune hydr ops and a peak bilirubin of 26 mg/dl; 2) a 25-week newborn with asphyx ia, hyaline membrane disease, grade IV intraventricular hemorrhage, ne crotizing enterocolitis, meconium peritonitis, sepsis, prolonged acido sis, and a peak bilirubin of 11.3 mg/dl; and 3) a 24-week newborn with asphyxia, hyaline membrane disease, grade III intraventricular hemorr hage, and a peak serum bilirubin of 18.5 mg/dl. Of the remaining 78 in fants who did not have kernicterus, peak bilirubin ranged from 3.6 to 22.5 mg/dl and 56% had bilirubin levels greater than that suggested as a criterion for exchange transfusion by NICHD Phototherapy Study guid elines; yet all but three were managed with phototherapy alone. Conclu sions. We conclude that kernicterus is currently an uncommon event in preterm infants, even when bilirubin levels ate allowed to rise above those previously thought to place the premature infant at risk.