Abstract: Light reflected from a pregnant woman's abdomen and fetus contained therein that has been received by a detector and converted into a reflected electronic signal may be received by a processor. A portion of the reflected electronic signal that is reflected from the fetus may be isolated and the isolated portion of the reflected electronic signal may be analyzed to determine a fetal hemoglobin oxygen saturation level of the fetus. The isolation may be achieved by synchronizing the reflected electronic signal with a fetal heartbeat signal and multiplying the synchronized reflected electronic signal by the synchronized fetal heartbeat signal.