Renal Response of the Fetus to Hypoxia

Abstract

Wide variations in urine composition and renal function are encountered during the immediate postnatal period (1,2). We proposed (2) that a possible cause for these variations was various degrees of disruption of maternal-fetal exchange leading to fetal and neonatal hypoxia (3,4). However, no correlation could be found between various aspects of renal function in the postnatal period and any clinical or biochemical evidence for an hypoxic insult (2). The infants studied all had one minute Apgar score of 7 or higher, were not acidotic and did not display blood pressure abnormalities. Despite this lack of correlation, there is considerable experimental evidence that hypoxia does influence renal function. It is possible that hypoxic insults during labor could be of such short duration or of an intermittent nature that they would not be evidenced by the clinical or acid-base status of the infants at birth (5). The purpose of the present experiment is to examine the renal response of the chronically instrumented lamb in utero to controlled hypoxia as well as acid-base and osmolar disturbances.