Comparing Fetal Pulse Oximetry with Scalp Ph.

OBJECTIVE: To determine whether pulse oximetry has the potential to replace scalp blood pH sampling in infants with abnormal cardiotacographs.STUDY DESIGN: The average scalp oximetry reading in labor recorded with an experimental N400 system was compared with fetal scalp blood pH.RESULTS: The average oximetry readings were unrelated to the PH of aerobically sampled fetal scalp blood. There was no subgroup of acidemic infants with a low oximetry reading.CONCLUSION: Pulse oximetry readings with present technology do not reflect scalp pH. The equipment is improving, but at this time pulse oximetry is not a simple alternative for scalp capillary blood sampling.