When is the vibroacoustic stimulation test (VST) typically utilized?

The vibroacoustic stimulation test (VST) is primarily utilized in conjunction with the nonstress test (NST) to assess fetal well-being. The NST monitors the fetal heart rate in response to fetal movements, and VST can enhance the test by providing vibrational and acoustic stimuli to encourage the fetus to move. This can help to determine if there is a reactive fetal heart rate response, which is indicative of healthy fetal function and well-being.

In practice, VST is used to improve the sensitivity of the NST when there are concerns about fetal movement or if the NST results are nonreactive. The stimulation prompts movement, which ideally results in an acceleration of the fetal heart rate, confirming that the fetus is receiving adequate oxygen and engaging in normal physiological responses.

While other testing methods like the contraction stress test (CST) or ultrasound assessments are important for different reasons, they do not typically incorporate VST as part of their protocols. Similarly, the use of VST with amniocentesis is not standard, as amniocentesis serves a different purpose, primarily related to genetic or biochemical analysis rather than immediate assessment of fetal heart rate reactivity. Therefore, the association of VST with the NST is the standard practice in obst