UMBILICAL ARTERIOVENOUS PO2 AND PCO2 DIFFERENCES AND NEONATAL MORBIDITY IN TERM INFANTS WITH SEVERE ACIDOSIS

OBJECTIVE: In term infants umbilical cord gas analysis is a poor predi ctor of immediate newborn complications associated with intrapartum as phyxia, unless the umbilical arterial pH is less than 7.00. We investi gated whether umbilical arteriovenous blood gas differences may better predict asphyxia-related complications. STUDY DESIGN: The study popul ation consisted of 82 term, nonanomalous, singleton, live-born infants with severe umbilical acidosis (pH <7.00). Umbilical arteriovenous pH , PCO2, and PO2 differences were correlated with Apgar scores and the presence of seizures, hypoxic-ischemic encephalopathy, cardiopulmonary and renal dysfunction, and abnormal development in the neonatal perio d. RESULTS: Umbilical arteriovenous pH, PCO2, and PO2 differences were interrelated (p < 0.0001), but these parameters correlated only weakl y with I-minute and 5-minute Apgar scores. An arteriovenous PCO2 diffe rence >25 torr was a highly sensitive and specific parameter in identi fying asphyxiated infants with seizures, hypoxic-ischemic encephalopat hy, cardiopulmonary and renal dysfunction, and abnormal development in the neonatal period. Arteriovenous Pop differences were less sensitiv e in the detection of neonatal morbidity than arteriovenous PCO2 diffe rences. CONCLUSION: Umbilical cord blood arteriovenous PCO2 difference s provide a new tool to predict neonatal morbidity and permanent neuro logic injury in term infants with perinatal asphyxia.