Fetal monitoring by physical methods II. Interpretation of phenomena

The results of assessing the fetal condition by means of the fetal electrocardiogram or the fetal heart rate pattern are by no means consistent. In the case of the fetal electrocardiogram this is due to several factors, such as lack of a standard lead, changes in the topographical relationship between the electrodes and the fetal heart caused by fetal movements, and incomplete knowledge about the direction of the fetal heart axis. The phenomena in the fetal heart rate pattern by which the fetal condition is assessed are insufficiently defined. Moreover, the physiologie mechanisms involved in the generation of the fetal heart rate pattern are, until now, not well understood.