Single injection polyfructosan clearance in normal and asphyxiated neonates.

The postnatal development of the glomerular filtration rate in 36 neonates has been evaluated by the single injection polyfructosan clearance method (GFRPfr) by studies performed at 0-1, 2-4 and 5-7 weeks of postnatal age. During the first weeks of life there is a rapid postnatal increase of GFRPfr of almost the same magnitude in term and preterm healthy infants. Thus the postnatal development of glomerular filtration rate is more closely related to extra-uterine excretory needs than to the maturatinal stage and gestational age at birth. In the asphyxiated neonates studied the GFRPfr was significantly lowered in the immediate postasphyxial stage while the infants were still hypoxemic. However the postnatal rise of GFRPfr in the time period following the postasphyxial stage was of the same order as in the non-asphyxiated healthy neonates.