Preliminary experience with intrapartum fetal pulse oximetry in humans

Electronic fetal heart rate (FHR) monitoring is commonly used to assess fetal well-being during labor. Nonreassuring patterns in many cases are associated with normal fetal acid-base condition, leading to unnecessary operative intervention. Fetal pulse oximetry has several potential advantages over FHR monitoring because it assesses not only pulse, but also arterial oxygen saturation and tissue perfusion. We describe our preliminary experience with the Nellcor N-400 Fetal Oxygen Saturation Monitor and FS-10 Oxisensor in 73 subjects during active labor at term. The mean (+/- standard deviation) duration of monitoring was 161.4 +/- 106.0 minutes, with sensor contact achieved 67.3 +/- 22.5% of the time during labor. Data were successfully recorded in all patients, with a reliable signal obtained 50.1 +/- 21.6% of the time during labor. The mean fetal oxygen saturation was 57.9 +/- 10.0%. The potential for research and clinical applications appears promising with further sensor and monitor development.