Threshold of metabolic acidosis associated with newborn complications.
OBJECTIVE
Our purpose was to determine the threshold of metabolic acidosis at delivery associated with newborn complications.


METHODS
This study was a matched case-control study of 174 term newborn infants. Three groups defined by umbilical artery base deficit at birth were 4 to 8 mmol/L, 8 to 12 mmol/L, and 12 to 16 mmol/L. Newborn complications during the 5 days after birth were documented. A composite complication score defined the magnitude of all complications in each neonate.


RESULTS
Moderate and severe newborn encephalopathy and respiratory complications and composite complication scores >3 were increased in the group with an umbilical artery base deficit of 12 to 16 mmol/L. Moderate or severe newborn complications occurred in 10% of newborns in the same group, whereas such complications occur in 40% of neonates with an umbilical artery base deficit >16 mmol/L at birth.


CONCLUSIONS
The threshold of fetal metabolic acidosis at delivery when moderate or severe newborn complications may occur is in an umbilical artery base deficit of 12 mmol/L. Thereafter, increasing metabolic acidosis is associated with a progression of severity of newborn complications.
Low
J A
JA
Department of Obstetrics and Gynecology, Queen's University, Kingston, Ontario, Canada.
Lindsay
B G
BG
Derrick
E J
EJ
D000138:Acidosis / Q000097:blood / Q000150:complications*; D016022:Case-Control Studies; D036861:Delivery, Obstetric; D004056:Differential Threshold; D005260:Female; D005333:Fetus / Q000378:metabolism*; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000453:epidemiology / Q000209:etiology*; D007744:Obstetric Labor Complications; D011247:Pregnancy; D011248:Pregnancy Complications; D014469:Umbilical Arteries