Does Fetal Acidosis Develop With Maternal Glucose Infusion During Normal Labor?

The actual effects of glucose infusion on fetal acid-base status were studied during 125 normal deliveries in which plasma glucose and acid-base parameters were determined after maternal infusion of either 10% glucose or Ringerʼs solution. After 80 minutes, mean (± SD) plasma glucose levels were significantly higher in the glucose group (N = 59) than in the Ringerʼs group (N = 66), both for the mother (183.6 ± 46.8 versus 95.3 ± 18.0 mg/dL) and the fetus (108.4 ± 41.4 versus 64.8 ± 16.2 mg/dL). Fetal plasma lactate concentrations did not differ between the glucose and the Ringerʼs groups, but were significantly lower in the fetuses delivered by elective cesarean section in both groups. With glucose administration, fetal pCO2 was higher and pH values were lower than in the Ringerʼs group. However, the magnitude of acid-base status changes, indicated by both pH and pCO2 shifts (ie, the difference between umbilical artery and scalp values), failed to differ between the two groups. In fetuses with progressing hypoxia, no differences in any of the acid-base parameters were observed between glucose and Ringerʼs administration. These data indicate that at a glucose infusion rate of 30 g/hour, fetal acidosis, when it occurs, results from hypoxia rather than from maternal glucose administration.