Tests on unborn babies such as ultrasound and heart rate are carried out to check their well-being. As a baby’s sleep periods can alter those results, various methods are used to wake the baby. Fetal vibroacoustic stimulation uses a hand held electronic device placed just above the pregnant woman’s stomach. Brief sounds are sent through her stomach to her baby. The review of trials found this method improves the effectiveness of the baby’s heart rate testing without changing the test’s reliability. More research is needed, especially into any possible adverse effects.
http://vibroacoustic.org/FrequencyInfo/Research%20Articles/Fetal%20Vibroacoustic%20Stimulation.pdf
Fetal Vibroacoustic Stimulation