Does skin pigmentation affect the accuracy of FSpO2 readings?
Based on the changes in blood volume and relative differences in light absorption with the cardiac cycle, pulse oximeters measure the oxygen saturation of arterial blood, which is the only part of the vasculature that normally pulsates. Because tissue such as skin, bone and the venous vasculature are generally considered non-pulsating, they do not enter into the pulse oximeter’s determination of oxygen saturation. Skin pigmentation for conventional (adult) pulse oximetry can affect signal quality if it is so dark that it does not allow light from the light emitting diodes to pass into and out of the pulsating vascular bed. Melanotic pigmentation is not well developed in most fetuses irrespective of ethnic group and should not interfere with FSpO2 readings.
