Usefulness of Urine Uric Acid/Creatinine Ratio in Neonate as an Early Detector of Perinatal Hypoxia: A Hospital-Based Observational Study

Abstract

Background : When a neonate is born under a hypoxic state, there is increased production of uric acid due to hypoxic tissue damage, which is excreted via the kidney, and the ratio of uric acid and creatinine (UA/Cr) in urine is used as an early predictor of perinatal hypoxia. Objectives : We conducted this study to compare urine UA/Cr ratio between normal and asphyxiated newborns and between different stages of HIE to evaluate its usefulness as a diagnostic and prognostic marker of perinatal asphyxia . Patients and method: This observational cross-sectional study is conducted for one year with 75 asphyxiated neonates in different stages of HIE and 75 healthy neonates as control. Uric acid and creatinine values are measured with an auto-analyzer from a single urine sample taken between 6 to 24 hours of birth. Results: We found urine UA(38 ±2.81 mg/dl vs 19.24±0.75 mg/dl ) and urine UA/Cr value (2.81±0.32 vs 1.40±0.13 ) significantly high in cases compared to control. Also, the urine UA and UA/Cr values are increasing with advanced stages of HIE (p <0.001). The optimal cut point value to predict HIE was at urine UA/Cr ratio of >2.45 with an AUC of 0.96, accuracy of 90%, sensitivity of 98.07% , specificity of 85.70% , PPV 78.46%, and NPV 98.82%. Conclusion: Urine UA/Cr appears to be a simple, inexpensive and reliable indicator of perinatal hypoxia for risk stratification based on functional impairment in the HIE babies.