Clinical experience with the Hewlett-Packard M-1350A fetal monitor: Correlation of Doppler-detected fetal body movements with fetal heart rate parameters and perinatal outcome

OBJECTIVE: Our purpose was to correlate measures of Doppler-detected fetal movements with standard fetal heart rate parameters and perinatal outcomes. STUDY DESIGN: This prospective, multiinstitutional trial used the Hewlett-Packard M1350A monitor to record simultaneous fetal heart rate baseline, variability, accelerations, decelerations, and number of fetal movements, and duration and percent of total time. These data were compared at 10- and 30-minute intervals during nonstress tests and were correlated with fetal heart rate baseline parameters and maternally perceived fetal movements and with outcomes of infants delivered within 7 days of the last test. RESULTS: At six centers 1704 actocardiograms from 884 third-trimester patients were analyzed. Doppler-detected fetal movement counts, durations, and percent of total time correlated weakly with all baseline fetal heart rate parameters (all values < 0.20). All fetal movement parameters increased significantly in successive 10-minute blocks and in periods of increased or normal fetal heart rate variability compared with those with fetal heart rate variability. The sensitivity, specificity, and predictive values of the percent of total movement time were comparable to those of standard nonstress test parameters. The risk of poor perinatal outcomes after nonreactive nonstress tests was lower in cases with fetal movements than in those without. CONCLUSIONS: Doppler actocardiography may help to discriminate fetal states during antepartum testing. It may prevent inappropriate diagnosis of fetal compromise when the nonstress test is nonreactive or nonreassuring. (AM J OBSTET GYNECOL 1994;170:650-5.)