Effects of low-frequency vibration on human term fetuses.

Thirteen healthy pregnant women between 37 and 41 weeks' gestational age were studied to examine effects of a 5-second external vibratory stimulus (100 Hz, square wave) on fetal heart rate, fetal breathing, and gross fetal body movement patterns. All fetuses were stimulated during an episode of low fetal heart rate variability (mean minute range ≤32 milliseconds for ≥5 minutes) lasting at least 5 minutes. There was an immediate and sustained increase in long-term FHR variability, number of FHR accelerations, and gross fetal body movements after stimulation. Fetuses made breathing movements more irregularly after vibratory stimulus. We hypothesize that external low-frequency vibratory stimulus, applied during episodes of low fetal heart rate variability, causes a change from a state of quiet sleep to a state of rapid-eye-movement sleep in healthy term fetuses.

[1]  R. Paul,et al.  Fetal acoustic stimulation testing. II. A randomized clinical comparison with the nonstress test. , 1986, American journal of obstetrics and gynecology.

[2]  R Gagnon,et al.  External vibratory acoustic stimulation near term: fetal heart rate and heart rate variability responses. , 1987, American journal of obstetrics and gynecology.

[3]  B. Richardson,et al.  A definition of human fetal apnea and the distribution of fetal apneic intervals during the last ten weeks of pregnancy. , 1980, American journal of obstetrics and gynecology.

[4]  L E Bernstein,et al.  Child and adult vibrotactile thresholds for sinusoidal and pulsatile stimuli. , 1986, The Journal of the Acoustical Society of America.

[5]  H. Prechtl,et al.  REFLEXES AND THEIR RELATIONSHIP TO BEHAVIOURAL STATE IN THE NEWBORN , 1968, Acta Paediatrica Scandinavica.

[6]  H. Prechtl,et al.  Are there behavioural states in the human fetus? , 1982, Early human development.

[7]  J. Patrick,et al.  Definition of sleep state in the newborn infant by heart rate analysis. , 1977, American journal of obstetrics and gynecology.

[8]  R. Gagnon,et al.  Stimulation of human fetuses with sound and vibration. , 1986, American journal of obstetrics and gynecology.

[9]  J. Read,et al.  Fetal heart rate acceleration in response to acoustic stimulation as a measure of fetal well-being. , 1977, American journal of obstetrics and gynecology.

[10]  H. Prechtl,et al.  Psychophysiological Studies in Newborn Infants , 1969 .

[11]  L. Leader,et al.  The assessment and significance of habituation to a repeated stimulus by the human fetus. , 1982, Early human development.

[12]  T. Blaschke,et al.  Nifedipine pharmacokinetics during preterm labor tocolysis , 1989, American journal of obstetrics and gynecology.

[13]  S. Schulze,et al.  Fetal behavioural states and controlled sound stimulation. , 1985, Early human development.

[14]  C. Hutt,et al.  Auditory Responsivity in the Human Neonate , 1968, Nature.

[15]  R. Gagnon,et al.  Human fetal responses to vibratory acoustic stimulation from twenty-six weeks to term. , 1987, American journal of obstetrics and gynecology.

[16]  G S Dawes,et al.  Improvements in the registration and analysis of fetal heart rate records at the bedside , 1985, British journal of obstetrics and gynaecology.