Evaluation of a continuous tissue pH monitor in the human fetus during labor.

Continuous tissue pH monitoring of the fetus was successfully conducted in 13 of 21 patients (61.9%) during labor. There was a significant correlation between the tissue pH and both the scalp capillary blood pH (r = 0.94, P less than 0.001) and the umbilical artery blood pH (r = 0.92, P less than 0.01). These findings confirm the accuracy of the tissue pH instrumentation in reflecting fetal acid-base status and support the potential usefulness of the instrumentation in perinatal medicine for continuous fetal acid-base monitoring.