Urinary uric acid/creatinine ratio as an additional marker of perinatal asphyxia

Purpose: To study the validity of urinary uric acid (UA) as a marker of per inatal asphyxia in term and premature infants. Methods: The urinary ratio of UA to creatinine (Cr) was obtained within 24 hours after birth in four groups of infants: 17 term infants and 18 prematu re infants with perinatal asphyxia, and 22 healthy term infants and 20 prem ature infants without perinatal asphyxia. Perinatal asphyxia was defined as an Apgar score of 3 or less at 1 minute or 5 or less at 5 minutes, and/or a first blood gas pH of less than 7.25 and a base deficit of at least 12 mm ol/L. Results; The urinary ratio of UA to Cr was significantly higher in term inf ants with perinatal asphyxia than in term infants without asphyxia (1.53 +/ - 0.71 vs 0.73 +/- 0.45; p < 0.005). The same result was found between prem ature infants with and without perinatal asphyxia (3.89 +/- 1.84 vs 2.45 +/ - 0.88; p < 0.01). The urinary ratio of UA to Cr in premature infants was s ignificantly higher than in term infants. When the urinary ratio of UA to C r was greater than 0.95, perinatal asphyxia was identified with a sensitivi ty of 80% and a specificity of 71% in term infants. In premature infants, a cut-off value of UA/Cr for perinatal asphyxia of 2.9 had a sensitivity of 71% and a specificity of 70%. Conclusions: The results of this study indicate that the urinary ratio of U A to Cr may be used as an additional marker of perinatal asphyxia in term a nd premature infants. In comparison with other markers such as xanthine, hy poxanthine, and ascorbic acid, it is a simple, quick, and inexpensive way t o detect hypoxic episodes in a neonatal intensive care unit within 24 hours after birth.