Neonatal hyperbilirubinemia and renal function.

It has been suggested that neonates with hyperbilirubinemia may have impaired renal function. In order to study this problem, creatinine clearance, and fractional tubular reabsorption of sodium and beta-2-microglobulin were measured in 22 jaundiced neonates with gestational ages ranging from 33 to 42 weeks and mean postnatal age of 3.9 days. These data were compared with those obtained from 23 nonjaundiced control infants matched for gestational and postnatal ages. In addition, follow-up studies of renal function were conducted in 18 of 22 study infants when serum bilirubin concentration was less than 11 mg/dl at a mean postnatal age of 7.6 days. No significant differences in CCr, T Na, or T beta 2M were observed. We conclude that when gestational age is greater than or equal to 33 weeks, modification of current management of infants with moderate hyperbilirubinemia is unnecessary to prevent nephrotoxicity.