Acoustic stimulation testing.

Abstract

The nonstress test is the most widely employed method of fetal health assessment. The current approach is to use the OCT or biophysical profile as a means of identifying the fetus at very high risk should the nonstress test be either nonreassuring or equivocal. The acoustic stimulation test may have a predictive ability similar to that of the biophysical profile and thus may be used to complement nonstress testing as early as 28 weeks' gestation. It reliably invokes a reactive NST in those fetuses destined to demonstrate reactivity with persistence in monitoring and facilitates more rapid and efficient testing. The acoustic test may have the additional benefit of providing a screening mechanism for anomalies in which neurologic performance is suboptimal. However, because the test has not been studied on large numbers of patients and because different applications of such stimuli may elicit differing responses, its adaptation for clinical use should be cautious at the present time.