ABSTRACT
Changes in renal blood ow shortly aer birth drive changes in the neonatal glomerular ltration rate (GFR). ere are marked changes in the proportion of cardiac output distributed to the kidneys throughout development and immediately following birth. e blood ow to the fully mature adult kidneys typically accounts for 20% to 30% of the cardiac output. is is in stark contrast to the developing fetal kidney, which receives 2.5% to 4% of cardiac output.1 In the rst 24 hours aer birth, this increases to 6% of the cardiac output and continues to increase to 10% of the cardiac
output at 1 week of life2,3 and to 15% to 18% of the cardiac output at 6 weeks.4 e dynamic changes in renal blood ow that occur following birth are driven by increased renal perfusion pressure and decreased renal vascular resistance.
