Intensive phototherapy has been used in the treatment of infants who required phototherapy for hyperbilirubinemia. With this modality, there is a concern about rebound in serum bilirubin levels after discontinuing phototherapy. This concern has led some physicians to recheck serum bilirubin levels after removing newborn infants from phototherapy, despite the American Academy of Pediatrics' recommendation that infants not be kept in hospitals for determination of repeat bilirubin levels after discontinuing phototherapy. Maisels and Kring determined the incidence for rebound hyperbilirubinemia after stopping phototherapy. In addition, they compared rebound in the group of infants who received phototherapy during their birth hospitalization with rebound in those who were treated after discharge and readmission to the hospital.

The study design was a retrospective analysis of the medical records of all term and near-term infants who were treated with photo-therapy for hyperbilirubinemia in a well-baby nursery. Two groups were studied: those who received phototherapy during their birth hospitalization and those who were readmitted for phototherapy after discharge from the nursery. All infants received intensive phototherapy, and rebound measurements were included if a bilirubin level was obtained between four and 48 hours after discontinuing phototherapy. Main outcome measures included infants who received phototherapy and the magnitude of the bilirubin-level rebound.

There were 303 term or near-term infants who met the inclusion criteria for the study. One hundred fifty-eight were treated with phototherapy during their birth hospitalization, while 144 were readmitted for hyper-bilirubinemia. Thirteen (8.2 percent) of the infants who received phototherapy during their birth hospitalization required repeat phototherapy after discontinuation of the initial phototherapy.

Only one infant in the readmission group required repeat phototherapy. Phototherapy was discontinued at a mean serum bilirubin level of 10.4 mg per dL (178 μmol per L) in the infants treated during birth hospitalization. Among those readmitted for phototherapy, the mean serum bilirubin level at discontinuation was 12.3 mg per dL (210 μmol per L). The average rebound level in the birth admission group of infants was 1.3 mg per dL (22 μmol per L), and it was 0.27 mg per dL (4.6 μmol/L) in the readmitted group.

The authors conclude that it is not necessary to keep infants in the hospital to check for rebound serum bilirubin levels in infants treated with phototherapy. They do recommend repeat serum bilirubin checks 24 hours after discharge to identify the small group of infants who have significant rebound in these levels. This is particularly important if phototherapy is discontinued at higher serum bilirubin levels than were used in this study.