[The effects of vibratory acoustic stimulation on fetal heart rate and body movement of normal fetuses at different gestational ages].
OBJECTIVE
To study the effects of vibratory acoustic stimulation (VAS) on fetal heart rate (FHR) and fetal movement (FM) of normal fetu at different gestational ages.


METHODS
435 normal second and third-trimester pregnancies were studied using real time ultrasonography. FHR baseline was recorded. Then a five-second VAS was given and FM and (or) FHR was observed. The results of vibroacoustic stimulation testing (VAS-T), sound-provoked fetal movement (SPFM) and the amplitude of FHR acceleration were evaluated.


RESULTS
(1) The fetus started to response to VAS from the 24th gestational week, but most could not reach the diagnostic criteria of VAS-T. The responses of FM were normal. (2) From 28 week on, 90% of the fetu showed marked FM and acceleration of FHR after VAS. Over 98% of the term babies were reactive. (3) The detective rates of SPFM appeared significantly earlier than that of VAS-T.


CONCLUSIONS
It suggested that the development of fetal nervous system was matured at 28 weeks, and the development of motor nerves was earlier than that of the autonomic nerves.
Li
Z
Z
Xinqiao Hospital, Third Military Medical University, Chongqin.
Wu
M
M
Du
B
B
D000161:Acoustic Stimulation; D005260:Female; D005324:Fetal Movement; D006340:Heart Rate, Fetal / Q000502:physiology*; D006801:Humans; D009420:Nervous System / Q000196:embryology; D011247:Pregnancy; D011446:Prospective Studies; D014732:Vibration