Comparison of cord purine metabolites to maternal and neonatal variables of hypoxia.

Umbilical arterial concentrations of purine metabolites were evaluated prospectively as markers of hypoxia. The results suggest that hypoxanthine accumulates in association with fetal acidosis and reduced levels of buffer base (P less than .01). Acute hypoxemia defined by umbilical arterial oxygen pressure was accompanied by elevation of uric acid concentrations (P less than .01). Fetal heart rate tracings with characteristics classically associated with fetal stress correlated with increased concentrations of hypoxanthine and xanthine (P less than .01). Therefore, intrapartum events may occur that are not documented by standard markers of perinatal hypoxia at delivery.