We attempted to determine the etiology and clinical significance of un
expected acidemia in otherwise healthy neonates. A retrospective revie
w was performed of the umbilical cord pH in 21,203 deliveries performe
d at Denver General Hospital, with an umbilical artery pH < 7.13 (3 SD
below the mean) selected as the definition of neonatal acidemia. Amon
g those neonates weighing > 2.5 kg with umbilical artery pH < 7.13, 76
were expected to have acidemia because of signs of severe fetal distr
ess. 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 exce
ss of $880,000 was spent performing routine umbilical blood pH determi
nations without any apparent clinical or legal benefit. Routine umbili
cal blood gas studies on all neonates does not appear to be indicated
for either clinical or legal reasons.