胎儿声振动刺激反应的研究

目的：了解不同孕龄胎儿对声振动刺激的反应。方法：对４３５例次正常中、晚期妊娠妇女进行声振胎心试验（ＶＡＳ－Ｔ）、声振胎动试验（ＳＰＦＭ），并对声振动刺激前、后胎心率变化规律进行前瞻性研究。结果：（１）从２４周开始，胎儿对声振刺激有反应，但大部分未能达到ＶＡＳ－Ｔ诊断标准，而胎动反应良好。（２）妊娠２８周开始，声振刺激后，９０％以上的胎儿出现显著的胎动、胎心率加速反应，足月胎儿反应率在９８％以上。（３）ＳＰＦＭ阳性率的显著提高早于ＶＡＳ－Ｔ。提示：２８周后胎儿神经系统发育已趋完善。胎儿运动神经的发育成熟早于植物神经。

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. Method: 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. Conclusion: 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.