Measurement of fetal scalp pH by continuous-recording scalp electrode and correlation with capillary blood pH

Experience with the use of a continuous-recording scalp electrode for fetal pH in subcutaneous scalp tissue is described. After initial problems, the correlation with capillary blood pH, taken by fetal scalp blood sampling, was found to be good, and it is concluded that this method is accurate enough to merit further trials in clinical practice. Residual technical problems remain which should not prove insurmountable.