Lipshitz J, Wade J E, Anderson G D, Sibai B M
Am J Obstet Gynecol. 1981 Jan 15;139(2):199-203. doi: 10.1016/0002-9378(81)90446-4.
The Corometrics 315 telemetry system is a commercially available unit which can transmit both fetal heart rate (FHR) and intrauterine or external pressure data to a standard fetal monitor. This system was evaluated in 40 patients, ten of whom were monitored simultaneously by telemetry and direct-wire fetal monitoring. Because of some differences in electronic engineering between the telemetry and direct fetal monitoring systems, the following differences were found: Comparison of the simultaneously obtained FHR recordings revealed that the telemetry system rejected most of the motion artifacts while maintaining true variability. There were no differences as regards readability, FHR, and beat-to-beat variability. The intrauterine pressure values were the same, although the telemetry system gave a smoother waveform with less motion artifact. The main advantages of the telemetry system were found to be: (1) The patient was free to move about and ambulate during labor. (2) It was possible to obtain uninterrupted monitoring while the patient was moved from the labor room to the delivery room and throughout the second stage of labor.
