Non-invasive monitoring of fetal oxygen saturation

Background. Monitoring of fetal heart-rate is routinely used to judge fetal well-being, though bradycardia is a late sign of hypoxia. Objective. We developed a non-invasive method to directly measure fetal arterial oxygenation. Material and Method. In order to catch the fetal signal, we applied a light source and a photodetector onto the abdomen of pregnant women of about 35 wks gestation. Results. Using sophisticated signal processing techniques (patent pending) we succeeded in separating fetal und maternal pulse signal to a sufficient degree to determine fetal arterial oxygen saturation. Discussion. Although during that first phase of investigation we restricted our study population to healthy pregnancies, there is no obvious reason why our method should not work under fetal pathology. Conclusion. We present a novel method for the monitoring of fetal well-being, measuring fetal oxygenation which if disturbed is the very first step in the chain of adverse events leading to fetal damage. Due to its non-invasive nature and proven clinical feasibility the presented method has the potential to make it the method of choice for prenatal, or intrapartum fetal monitoring.