Fetal pulse oximetry--a preliminary report on sensor precision determined by dual sensor studies.

OBJECTIVE

The objective of the study was to test the clinical reproducibility of intrapartum fetal pulse oximetry.

STUDY DESIGN

This observational study was performed on the labour ward and 27 women were recruited. After obtaining written consent two sensors were placed on the same fetus.

RESULTS

More than 82 h of valid paired data was obtained and preliminary analysis is presented. The mean signed difference between dual sensors was -0.04%Sat (S.D. 8.12%Sat) The precision for a single sensor was +/-5.74%Sat. The most common absolute saturation difference was 1%Sat (median: 46%Sat, 5th and 95th centiles: 29 and 60%Sat, respectively). Occasions when the difference was outside 2 S.D. were of short duration.

CONCLUSIONS

There is good clinical reproducibility with the latest sensor design. The frequency distribution of oxygen saturation values lends support to 30-60%Sat as the normal range in the human fetus.