Vibroacoustic stimulation explained

Vibroacoustic stimulation (VAS), sometimes referred to as fetal vibroacoustic stimulation or fetal acoustic stimulation test (FAST), is the application of a vibratory sound stimulus to the abdomen of a pregnant woman to induce FHR (fetal heart rate) accelerations. The presence of FHR accelerations reliably predicts the absence of fetal metabolic acidemia. Vibroacoustic stimulation is typically used during a nonstress test (NST).^{[1] [2]}

In 2013, the Cochrane Database of Systematic Reviews concluded that there was insufficient evidence from randomized trials to support its use to assess fetal well-being in labor.^[3] A related Cochrane Review, however, concluded that its use in antenatal testing did reduce the incidence of non-reactive cardiotocography and the overall testing time.^[4]

Notes and References

1. Book: Chervenak, Frank A. . Kurjak, Asim . Textbook of Perinatal Medicine, Second Edition (Two Volumes) . Informa Healthcare . 2006 . 963 . 1-84214-333-6 .
2. Book: Association of Women’s Health, Obstetric, and Neonatal Nurses . Fetal Heart Monitoring: Principles and Practices. AWHONN. Audrey Lyndon, Linda Usher Ali. 3rd. 2005. Kendall/Hunt Publishing Co. Dubuque, IA . 978-0-7575-6234-1.
3. East . C. E. . Smyth . R. M. . Leader . L. R. . Henshall . N. E. . Colditz . P. B. . Lau . R. . Tan . K. H. . East . Christine E . Vibroacoustic stimulation for fetal assessment in labour in the presence of a nonreassuring fetal heart rate trace . 10.1002/14651858.CD004664.pub3 . The Cochrane Database of Systematic Reviews. 1 . CD004664 . 2013 . 1 . 23440793 . 7212002 .
4. Tan . K. H. . Smyth . R. M. . Wei . X. . Tan . Kelvin H . Fetal vibroacoustic stimulation for facilitation of tests of fetal wellbeing . 10.1002/14651858.CD002963.pub2 . The Cochrane Database of Systematic Reviews. 12 . CD002963 . 2013 . 12 . 24318543 .