Postnatal development of renal function.

Renal function in the newborn is both qualitatively and quantitatively different from older infants, children and adults. Moreover, gestational age is of great importance in the interpretation of renal functional differences. These differences in renal function should not be viewed as solely immaturity per se but rather as functional adaptations to the needs of growth and development in many instances. Although the neonatal kidney is operating at a level appropriate for a given age, the decreased functional reserve makes it more vulnerable to stressful conditions. However, the low GFR and some of the decreased transport properties may actually be of benefit to the neonate. With respect to medications, one benefit of these neonatal differences appears to be less nephrotoxicity for certain drugs in the newborn compared with the adult.