Our first Aim is to describe how common a sudden decrease in renal function happens in premature infants in a neonatal intensive care unit. We also want to see how a sudden loss of renal function affects survival. Finally, we will explore non-invasive markers to identify a sudden decrease in renal function from urinary samples.

Advancements in the field of peri-natal medicine has improved the survival of critically ill neonates but yet many still do not survive, and many more are left with long-term damage to vital organ systems. Very little data is available on the impact that acute kidney injury (AKI) has on survival in premature infants, but adult and pediatric studies that show that even mild AKI independently impacts survival after correcting for severity of illness. The role that AKI impacts survival in premature infants is likely to be greater than adults as this acute injury occurs in context of impaired and ongoing kidney development..

Our ability to improve outcomes in children and adults with AKI has been hampered by the inability to recognize AKI early in the disease process. Thus, the work on early non-invasive biomarkers of renal injury has brought great optimism to the field of AKI. Serum and urinary levels of neutrophil gelatinase-associated lipocalin (NGAL), urinary interleukin 18 (IL-18) others are markedly elevated several hours after AKI as opposed to serum creatinine which takes days to rise after the inciting event. Early non-invasive biomarkers of AKI have not been tested in premature infants.

Inclusion criteria - infants (birthweight 500-1500g) be asked to participate in the study. • Exclusion criteria - Infants with prenatal renal ultrasound diagnosis of severe hydronephrosis or other known renal abnormalities will be excluded

Inclusion Criteria:

• 500-1500 grams birthweight
• >=25 weeks gestation

Exclusion Criteria:

• infants who do not survive 24 hours of life
• infants with severe congenital abnormalities

Premature Infants 500-1500grams birthweight >=25 weeks gestation