ABSTRACT
In 1822, Kergaradec described auscultation of the fetal heart sound as the only method by which fetal life and well-being have been assessed. Half a century later, using improved equipment, Hon and Hess succeeded in recording fetal ECG continuously through the maternal abdominal wall. Their recordings allowed an analysis of the actual fetal cardiac activity with regard to its regularity and rhythm. Fetal activity and uterine contractions are monitored externally by a device which is strapped to the mother’s abdomen, preferable over the uterine fundus. The baseline fetal heart rate (FHR) represents a result of intrinsic rate of contractions of the fetal heart as modified by the mediatory action of both parts of the autonomic nervous system, the sympathetic and the parasympathetic. Fetal tachycardias may also be seen without any apparent etiological cause similar to paroxysmal atrial tachycardia of the adult. Sinusoidal pattern is characterized by the absence of short-term variability and preservation of the long-term variability of the FHR.
