Fetal electrocardiogram obtained with subcutaneous maternal electrodes. A new method

The low voltage of the fetal heart signals and the usual background interference are the main obstacles in obtaining clear fetal electrocardiographic tracings with a high signal-to-noise ratio. By the use of subcutaneous needle electrodes, impulses from the maternal abdominal wall can be short-circuited. Fetal heart potentials with higher amplitude and less background noise are thus recorded. Fetal viability, presentation, multiple pregnancy, and congenital arrhythmias were diagnosed antenatally by means of the fetal ECG with subcutaneous electrodes and were later correlated with the outcome of the pregnancy. More than two hundred tracings were performed with 98 per cent accuracy.