A non-invasive optical technique for intrapartum fetal monitoring: preliminary clinical studies.

A relatively new optical method based on near infra-red spectroscopy was evaluated in preliminary clinical trials for noninvasive intrapartum fetal monitoring. The measurements were performed using mainly the light reflection mode of monitoring. Continuous monitoring of changes in the concentrations of oxygenated and deoxygenated haemoglobin and thus changes in total haemoglobin concentration in the fetal brain was achieved. It was found that uterine contractions can influence in a distinctive manner the near infra-red derived cerebral haemoglobin concentration changes in the fetus. The results indicate that near infra-red spectroscopy could offer a non-invasive real-time monitoring method for in vivo monitoring of blood oxygenation in the fetal brain. We conclude that this technique may be useful for intrapartum fetal monitoring and in predicting fetal cerebral hypoxia.