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 cardiotocographs.


METHODS
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.


CONCLUSIONS
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.
Johnson
N
N
Department of Obstetrics and Gynaecology, Leeds General Infirmary, England, U.K.
McNamara
H
H
Montague
I
I
Aumeerally
Z
Z
Lilford
R J
RJ
D001784:Blood Gas Analysis / Q000592:standards*; D005323:Fetal Monitoring / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010092:Oximetry / Q000295:instrumentation / Q000592:standards*; D015203:Reproducibility of Results; D012535:Scalp / Q000098:blood supply*