Arterial cord blood hypoxanthine: a measure of intrauterine hypoxia?

Abstract

In order to evaluate the concentration of hypoxanthine in the cord blood as an indicator of intrauterine hypoxia, hypoxanthine was determined in the arterial and venous cord blood of 49 randomly chosen newborns and in the peripheral venous blood of their mothers. In addition, 5 young, nonpregnant women were investigated. Term babies with signs of probable intrauterine hypoxia (fetal distress, scalp blood or arterial cord blood pH less than 7.19, and/or Apgar score of less than 5 at 1 min) had hypoxanthine levels (19.8 +/- 3.5 mumol/l) consistently above the mean for normals. However, there was a large variability of hypoxanthine values in normal babies (16.1 +/- 5.7 mumol/l) and in those with isolated signs of fetal distress (14.6 +/- 6.9 mumol/l). There was no general correlation between the levels of hypoxanthine in arterial cord blood and arterial cord blood pH (r = -0.15) or between the levels of hypoxanthine in arterial cord blood and the Apgar score at 1 min (r = -0.05) or between the levels of hypoxanthine in arterial cord blood and the Apgar score at 1 min (r = -0.05). At delivery, all mothers had higher levels of hypoxanthine than nonpregnant women (16.0 +/- 6.8 vs. 7.6 +/- 2.1 mumol/l; p less than 0.001). The maternal hypoxanthine values correlated closely with those of the venous cord blood (r = 0.72; p less than 0.001). Positive arterio-venous differences in the cord blood increased with progressively higher levels of hypoxanthine in arterial cord blood (r = 0.53; p less than 0.001), indicating a clearance through the placenta.(ABSTRACT TRUNCATED AT 250 WORDS)