Doppler recording of fetal movement: clinical correlation with real-time ultrasound

Processed Doppler signals can be used to detect fetal movements during antepartum fetal heart rate (FHR) testing. The purpose of this project was to evaluate the ability of a commercially available Doppler system, the Toitu Fetal Actocardiograph MT-320, to detect and discriminate various fetal activities during routine antepartum FHR testing. Simultaneous visualization with real-time ultrasound allowed correlation of isolated and complex fetal activities with the processed actograph signals. This apparatus was able to detect 95.9% of all major fetal movements observed, 94.3% of isolated fetal movements, 95.6% of isolated spinal flexion-extension, 97.1% of isolated rolling movements, and 100% of all multiple (P less than .001) fetal movements. Based on the amplitude (P less than .0001) and duration of the isolated actograph signals, it was possible to discriminate among fetal limb movements (mean amplitude 87.3 units, mean duration less than 2.0 seconds), spinal flexion-extension movements (66.3 units, 14.8 seconds), and rolling movements (43.8 units, 22.1 seconds). The routine detection of fetal breathing, hand movements, and rapid eye movements appears to be beyond the sensitivity of this particular apparatus. The ability to evaluate fetal activity reliably may be clinically useful during routine antepartum FHR testing.