Are recommended phototherapy thresholds safe enough for extremely low birth weight (ELBW) infants? A report on 2 ELBW infants with kernicterus despite only moderate hyperbilirubinemia

Two extremely low birth weight (ELBW) infants developed characteristic signs of kernicterus at 4 and 8 months corrected age despite only moderate neonatal hyperbilirubinemia (peak serum bilirubin <10 g/dl) and phototherapy being applied according to current guidelines. Both girls were from twin pregnancies and had fetal complications (donor in a twin-twin transfusion syndrome and acardius-acranius malformation in the second twin, respectively), connatal anemia (initial hematocrit 30%), and mild acidosis after birth. They had been neurologically normal at discharge except for abnormal otoacustic emissions (OAE). At the time kernicterus was diagnosed, both infants were nearly deaf, showed severe psychomotor retardation with dystonic features and had marked bilateral hyperintensities in the globus pallidum on MRI. Based on these and similar cases from the literature, we question whether current phototherapy guidelines are appropriate for high-risk ELBW infants. Lower thresholds may be preferable, at least if additional risk factors, such as anemia, are present.