Urinary hypoxanthine, xanthine and uric acid excretion in newborn infants with perinatal complications.

The concentration of hypoxanthine, xanthine and uric acid in the first 24-h urine of 105 newborn infants was measured densitometrically by thin-layer chromatography. 45 of them had moderate or severe perinatal complications. Among these newborns, 26 infants with perinatal complications (58%) and 4 infants without perinatal complications (7%) had an elevated urinary excretion rate of hypoxanthine. Urinary xanthine was not increased, uric acid was slightly higher in the group of infants with perinatal complication. It seems that a crucial mark is involved, if the rate of hypoxanthine exceed 15% of the total urinary oxypurine excretion, or, if related to urinary creatinine, more than 0.075 mumol hypoxanthine/mumol creatinine. Apparently, with hypoxic newborns increased values of urinary hypoxanthine excretion can be used to quantify the lack of oxygen retrospectively.