To study the effect of vibro-acoustic Stimulation on high and low fetal heart rate (FHR) variabï¿½ity episodes.Prospective control study, in 2l high risk pregnancies between 32 to 39 weeks gestation. FHR pattern was recorded with cardiotocograph (CTG). After 5 min low FHR variability a vibro-acoustic stimulator was activated in contact with or above the maternal abdomen (sham) on a random basis oh two consecutive days, and CTG was continued to obtain a complete high and low FHR variability cycle. Complete high and low FHR variability cycleswere obtained in 12 patients with mean recording time of 129.5 minutes (rï¿½nge 69 ï¿½ 185 min). The mean baseline FHR increased by 32.5 + 9.4 bpm after contact vibroacoustic Stimulation, but remained unchanged after shamStimulation. Mean duration of high FHR variability was 56.6 + 32.9 min and 47.3 + 23.7 min,respectively, and mean duration of the consecutive low FHR variability episode was similar after contact and sham Stimulation. The complete cycles were 71.1 ï¿½ 34.7 min and 66.2 + 21.2 min, respectively. Vibroacoustic Stimulation induced an abrupt change from low to high FHR variability, but the complete cycle of high and low FHR variability was not altered, when compared with the corresponding cycle following sham Stimulation on the same fetus.
- Fetal heart
- vibro-acoustic Stimulation