[The prognostic value of the acoustic stimulation test for fetal wellbeing and neonatal status. Controlled acoustic stimulation of the fetus in the last pregnancy trimester].

Fetal heart frequencies and fetal movements were examined in 57 cases simultaneously by antepartal cardiotocogram and by mothers in the third trimenon of their pregnancy. 163 CTGs were monitored and two different groups defined. One group of 34 healthy newborns was compared with a group of 18 small for gestational age fetuses (birth weight less than 25th percentile of birth weight). The fetal heart rate and movements response to sound stimulation was studied. Fetuses appropriate for gestational age showed significantly higher activity in heart rate accelerations and movements following sound stimulation (1-2 kHz, 120 dB, 20 sec.) compared with the group of SGA fetuses. The study showed that the maternal perception of fetal activity is a suitably complementary method to assess fetal wellbeing. Measuring by maternal perception, it could be demonstrated that fetuses appropriate to gestational age reached a higher activity (16.5 p.c. monitoring period) as compared with 8.0 p.c. of fetal movements registered by mothers in the group of small for gestational age fetuses.