The pH of neonatal cord blood, which is usually low, i.e., its normal pH average is 7.25, may be associated with mild hypoxia during delivery of the fetus. After delivery of the fetus, cord blood is quickly collected for blood gas analysis, and the diagnosis of neonatal asphyxia is made based on the results of the blood gas analysis (including blood pH, oxygen saturation, partial pressure of carbon dioxide, etc.) in conjunction with the Apgar score. If the fetus is in a state of hypoxia, it may produce excessive CO2, lactic acid accumulation, and then exhibit acidosis, which is manifested as a decrease in pH. In recent years, with the gradual and widespread use of umbilical cord blood gas analysis in clinical practice, this method can not only reflect the outcome of blood gas changes during labor and delivery, but also is simple and easy to perform, does not cause any trauma to mothers and infants, and can provide immediate and important feedback information for clinical assessment of the acid-base status of newborns at birth. If the pH of the cord blood of a newborn is severely decreased (usually <7.0), the newborn should be alerted to ischemia and hypoxia, and urgent treatment should be sought from a physician to avoid serious consequences.