Combination of vibroacoustic stimulation and acute variables of mFBP as a simple assessment method of low-risk fetuses.

OBJECTIVES

To observe a rate of fetal breathing and gross body movement appearance as physiologic reactions to the external vibroacoustic stimulation (VAS) and to establish a rapid and reliable antepartal method for accurate selecting of non-compromised fetuses in the low-risk population.

METHODS

Actual condition of 742-term and near-term structurally normal and otherwise healthy singleton fetuses with favourable outcome was assessed by previously established combination of the modified fetal biophysical profile and VAS. Only inactive fetuses at the beginning of the testing were included in the study. The combined biophysical testing has been started by a transabdominal real-time ultrasound examination, followed by vibroacoustic stimulus applied over the fetal head for 5 s during fetal quiescence. Fetal breathing and gross body movements were observed with particular attention in each case at measured time intervals from the application of external VAS until the moment at which either the first 60-s episode of breathing movements or all three fetal gross body movements were detected. Obtained results have been presented numerically in 5-min periods and cumulative percentages.

RESULTS

After the external VAS, 84.5% of studied fetuses successfully manifested their normal breathing or gross body movements in the first 5 min of the modified biophysical testing. Furthermore, approximately 96% of them were able to demonstrate at least one of these two biophysical activities after 6-7 min.

DISCUSSION: Because of its simplicity, non-invasiveness, independence of precise gestational dating, reproducibility and immediate individual results, ultrasonographic observation of normal fetal breathing and/or gross body movements after the external VAS stands a real chance to become a nearly optimal antenatal test for accurate and rapid information of actual non-compromised fetal condition. Authors strongly believe that the described antenatal method should represent a rather efficient assessment procedure of fetal well-being in late pregnancy, performed during regular antenatal visits.