Criteria of Modanlou and Freeman for the True Sinusoidal Heart Rate (SHR) Pattern on the Cardiotocogram

 

Parameters:

(1) fetal heart rate in beats per minute (vertical axis)

(2) time (horizontal axis)

 

Features of ture SHR:

(1) baseline fetal heart rate stable and from 120 to 160 beats per minute

(2) range for fetal heart rate amplitude usually between 5 to 15 beats per minute

(3) 2 to 5 cycles per minute in a sinusoidal pattern

(4) oscillation of sinusoidal wave above and below the baseline

(5) minimal short-term variability (relatively uniform pattern)

(6) absence of normal fetal heart rate variability or reactivity