Umbilical Arterial Lactate Research Articles

Acid-base characteristics of fetuses with intrauterine growth retardation during labor and delivery

The maternal and fetal cord blood from 37 infants with intrauterine growth retardation (IUGR) and 108 normal growth (AGA) infants were compared for lactate, pH, and blood gas values in an attempt to find whether there is any difference in stressed response in IUGR fetuses during labor and delivery. Both maternal and fetal blood lactate levels increased with progression of labor, fetal lactate being higher than the maternal lactate. Without intrapartum fetal heart rate decelerations, IUGR fetuses did not show a difference in umbilical arterial lactate, pH, and blood gases, compared to AGA fetuses. With intrapartum fetal heart rate decelerations, IUGR fetuses demonstrated a significantly higher lactate level than that of AGA fetuses. We conclude that IUGR fetuses tolerate labor less well than do AGA fetuses. In the presence of late decelerations, earlier intervention is preferable because of the increased likelihood of metabolic acidosis.

Assessment of metabolic state and anaerobic metabolism in the normal newborn infant

1.1. The normal infant at the end of normal labor and delivery is receiving a significant volume of oxygen, excreting carbon dioxide efficiently, and demonstrates a buffering capacity equal to the normal obstetric patient. There is no evidence of anaerobic metabolism as expressed by excess lactate with an anaerobic metabolic rate of less than 3 per cent.2.2. The brief period of hypoxia associated with the epidural effect demonstrates the limited reserve of the fetal metabolic state with a significant reduction of buffer base, increase of excess lactate, and threefold increase of anaerobic metabolic rate to 9 per cent.3.3. The characteristics of fetal tissues are well expressed by excess lactate, umbilical artery lactate, and buffer base levels. The continuing function and compensatory efficiency of the placenta is expressed by the umbilical vein lactate and buffer base levels.