ABSTRACT
Initially described in the chronically instrumented fetal lamb (Dawes, Fox, Leduc, & Richards, 1972), the organization of different fetal biophysical variables such as electrocortical activity, fetal breathing activity, and fetal eye movements into well-defined patterns corresponding to different fetal behavioral states has provided the physiological basis for assessing fetal health (Patrick, 1989). More recently, it has been observed that transabdominal vibroacoustic stimulation (VAS) can reproducibly alter fetal behavioral activity (Gagnon, Hunse, Carmichael, Fellows, & Patrick, 1987a, 1987b). As a result, fetal behavioral responses to VAS have been suggested as a new and effective tool to discriminate between the healthy and compromised fetus (Smith, Phelan, Platt, Broussard, & Paul, 1986). Unfortunately, the introduction of VAS in clinical practice has rapidly disseminated prior to the establishment of adequate knowledge of its underlying physiological mechanism and its effectiveness as a clinical tool. Therefore, this review concentrates on the developmental aspects of fetal behavioral responsiveness to sound and vibration under normal and pathological conditions. The clinical significance of the fetal behavioral responses to a changing maternal environment is also described.
