The Normal Fetal Electrocardiogram, with a Pro-Posed System of Standardized Terminology

A system of standard electrode and patient positions for fetal electrocardiography as suggested by an international ad hoc committee, is presented. The variation in the accuracy of the fetal ECG technique during gestation is shown and discussed. Existence of two peaks of high accuracy, at 22 weeks and at term, is shown. Normal values for the duration of the fetal QRS are shown to increase from 0.026 second at 20 weeks to 0.040 second at tern. Normal values and ranges for fetal heart rates and the amplitudes of the fetal QRS are reported.