Objective: To study the renal function in term newborns with perinatal asphyxia including urinary excretion of β2 microglobulin (β2M).
Methods: This case control study included 50 term newborn babies with perinatal asphyxia and 50 normal babies as matched controls. In all cases, asphyxia grading (using Apgar score) and Hypoxic ischemic encephalopathy (HIE) staging (Sarnat and Sarnat) were done. Blood and urinary parameters (including β2M) for renal function were done in all and Fractional excretion of sodium (FENa) and Renal failure index (RFI) were calculated. The renal parameters were compared within subgroups as well as controls using analysis of variance test and the independent samples t test.
Results: Acute kidney Injury (AKI) was noted in 56 % of cases (24 % prerenal and 32 % intrinsic type). All 9 babies who died had AKI. Serum parameters like urea, creatinine, sodium and potassium had better correlation with the renal function as compared to urine parameters. All individual urine parameters except β2M showed wide variations. FENa, RFI and urinary β2M increased with increasing severity of asphyxia and HIE staging.
Conclusion: AKI is common in term babies with perinatal asphyxia. FENa and RFI are useful parameters for assessing the renal function and urinary β2M is a good biomarker for diagnosis and prognosis of acute tubular injury in term babies with perinatal asphyxia.