Fetal motorical and heart response to sound stimulus in different behavioral states

In 32 fetuses from 37 to 41 weeks' gestation, motorical and heart rate response time, as well as the influence of arousal state on that time were tested. Motorical response time was defined as the time from external stimulus to fetal movement. Heart rate response time was defined as the time from stimulus to the increase in baseline of 15 beats/min. Wide low frequent sound was used as external stimulus. No correlation could be found between motoric and heart rate response time (R = 0.26652). Among the various arousal states the lower arousal state had a significantly longer motorical and heart rate response time.