Figure 3 (Illustration 3)
Schematic illustration of IA of FHR with acceleration: An acceleration
can be inferred when a rise of FHR of 15 bpm or more is observed on
Doppler-device display, preceded by a normal FHR baseline and return to
it after the acceleration. This is difficult to detect
precisely/subjectively while counting fetal heart beats over a minute
with Pinard stethoscope. The total count over 1 minute spuriously gives
an abnormally high figure (170 bpm) instead of a true baseline of 155
bpm. Even the cumbersome ‘multiple count strategy’4 is
less accurate than simply observing the numerical FHR display on the
Doppler-device.