Vibroacoustic stimulation.

Vibroacoustic stimulation of the human fetus profoundly alters fetal behavior and heart rate. Many authors have reported success using this technique to improve the efficiency of antepartum fetal heart rate testing without changing the predictive reliability of the tests. Vibroacoustic stimulation has other potential advantages in the antepartum assessment of fetal well-being and in provoking fetal activity to improve ultrasonic visualization. From an experimental standpoint, vibroacoustic stimulation offers a unique opportunity to assess how the fetus responds to the external environment. The available information suggests that exposure of the fetus to vibroacoustic stimulation is clinically safe. Additional research is needed to characterize the optimal frequency, duration, intensity, and choice of stimulus to provide consistent responses. The literature presents a confusing array of studies using different methods, which makes comparison of results among institutions and investigators difficult. Vibroacoustic stimulation appears to be a reasonable and safe clinical technique. Additional prospective investigation is necessary to characterize further how this technique can be more useful clinically.