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Updated: Aug 29, 2026

Biochemical Measurement of Neonatal Hypoxia
Published on: August 24, 2011
Umbilical cord blood gas analysis at delivery
J A Thorp1, G A Dildy, E R Yeomans
1Department of Ostetrics and Gynecology, Saint Luke's Hospital of Kansas City, MO 64111, USA.
Fetal acid-base status is the end point that all antepartum and intrapartum surveillance tools are designed to assess, either directly or indirectly. Umbilical arterial blood pH is normal in 80% of depressed newborns, thereby proving the absence of birth asphyxia both in the delivery room and in the courtroom. The technique, normal ranges, and risks, benefits and cost analysis of routine versus selected umbilical blood sampling are considered. The American College of Obstetricians and Gynecologists recommends performing umbilical blood sampling for acid-base analysis in selected deliveries. However, in our opinion routine umbilical blood sampling at all deliveries has merit.
Fetal acid-base status is the end point that all antepartum and intrapartum surveillance tools are designed to assess, either directly or indirectly. Umbilical arterial blood pH is normal in 80% of depressed newborns, thereby proving the absence of birth asphyxia both in the delivery room and in the courtroom. The technique, normal ranges, and risks, benefits and cost analysis of routine versus selected umbilical blood sampling are considered. The American College of Obstetricians and Gynecologists recommends performing umbilical blood sampling for acid-base analysis in selected deliveries. However, in our opinion routine umbilical blood sampling at all deliveries has merit.
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