The neonate with unexpected acidemia

We attempted to determine the etiology and clinical significance of unexpected acidemia in otherwise healthy neonates. A retrospective review was performed of the umbilical cord pH in 11,203 deliveries performed at Denver General Hospital, with an umbilical artery pH < 7.13 (3 SD below the mean) selected as the definition of neonatal acidemia. Among those neonates weighing > 2.5 kg with umbilical artery pH < 7.13, 76 were expected to have acidemia because of signs of severe fetal distress. There were 59 neonates with unexpected acidemia, having umbilical artery pH < 7.13, with no definite etiology found. In 96% of cases of unexpected acidemia, the neonates were discharged with their mothers, while 84% of the expected cases went home with their mothers. In excess of $880,000 was spent performing routine umbilical blood pH determinations without any apparent clinical or legal benefit. Routine umbilical blood gas studies on all neonates does not appear to be indicated for either clinical or legal reasons.