ABSTRACT
OBJECTIVES: The objectives of this study is to compare the differences of fetal heart rate (FHR) variables between preterm and term pregnancies after acoustic stimulation using computerized analysis of fetal heart rate. METHODS: Eighty-two normal pre-term and term pregnancies entered to this study after conventional 20-minutes nonstress test(NST) and 10-minutes acoustic stimulation test (AST). Acoustic stimulations were performed using Fetal Acoustic Stimulator (Model 146, Corometrics, US). We analyzed the FHR response after acoustic stimulation using our on-line computerized FHR analysis system, HYFM-I & II software. The changes of loss of signal, baseline FHR, variability, number of fetal movements, and number of FHR accelerations were analyzed numerically. RESULT: The mean baseline FHR was increased in term pregnancies from 141+/-7.0bpm to 152.7+/-9.7bpm, and in preterm pregnancies from 144.6+/-6.8bpm to 156.8+/-10.2bpm, respectively. The mean baseline FHR was significantly increased in both term and preterm pregnancies (p<0.01. paired t-test). The variability of FHR was increased in term pregnancies from 18.2+/-6.4bpm to 22.6+/-5.0bpm and in preterm pregnancies from 17.8+/-5.5bpm to 22.7+/-5.9bpm, respectively. The variability of FHR was also significantly increased in both term and preterm pregnancies. (p<0.01. paired t-test) CONCLUSION: The mean baseline FHR and the variability of FHR was significantly increased both preterm and term pregnancies. But the difference of each FHR variables between preterm pregnancies and term pregnancies was not statistically significant in this study.