Cross-correlation of fetal cardiac and somatic activity as an indicator of antenatal neural development.

OBJECTIVE In this study, we wanted to model the emergence of coupling between fetal cardiac and somatic activity in normal and at-risk fetuses. STUDY DESIGN One hundred six fetuses of uncomplicated pregnancies were longitudinally monitored at 20, 24, 28, 32, 36, and 38 weeks of gestation by using a fetal actocardiograph and computerized data collection. Twenty-six fetuses of complicated pregnancies were also included. Statistical time series analysis techniques were used to examine the relation between fetal movement and fetal heart rate. RESULTS A linear increase was found in the magnitude of the cross-correlation function between fetal movement and fetal heart rate as gestation advanced, with coalescence around a peak lag of 5 seconds by 32 weeks. Fetuses that delivered before term evidenced accelerated fetal movement and fetal heart rate coupling, whereas fetuses affected by deleterious conditions showed a decline in developmental trajectory. CONCLUSIONS The cross-correlation between fetal cardiac and somatic activity is an indicator of neuroregulation in human fetuses.