Computerized fetal heart rate monitoring after vibroacoustic stimulation in the anencephalic fetus.
BACKGROUND
To quantify changes in fetal heart rate (FHR) parameters after vibroacoustic stimulation (VAS) and to evaluate the usefulness of VAS testing (VAST) in anencephalic fetuses. Our findings may also help to clarify the route(s) of vibration and sound transmission during VAST.


METHODS
We obtained the antepartum FHR tracings of 16 anencephalic fetuses, including both the nonstress test (NST) and VAST. Using a computerized monitoring system, HYFM, we determined all FHR parameters from data collected for 10 min before and 10 min after VAS, at successive gestational stages.


RESULTS
We observed three false reactive responses at term. The false reactive rate for VAST (3/16) was higher than that for NST (1/16). No FHR parameters increased significantly after VAS except for the number of fetal movements (FM), which increased significantly in all gestational groups (25th-32nd and 33rd-40th weeks).


CONCLUSIONS
These findings call attention to an increased probability of a false reactive response in VAST analysis, when the fetus is affected by a CNS disorder. Increased numbers of FM after VAS suggest that the vibratory pathway is more likely to elicit fetal response than the auditory pathway in this setting, and that the vibratory stimulation travels by subcortical rather than by cortical pathways.
Park
Yong-Jin
YJ
Department of Mechanical Engineering, College of Engineering, Yonsei University, Seoul, Republic of Korea.
Park
Seon-Hye
SH
Kim
Young-Jae
YJ
Hoh
Jeong-Kyu
JK
Park
Young-Sun
YS
Park
Moon-Il
MI
D000161:Acoustic Stimulation; D000757:Anencephaly / Q000503:physiopathology*; D005323:Fetal Monitoring / Q000379:methods*; D005333:Fetus / Q000503:physiopathology*; D006340:Heart Rate, Fetal / Q000502:physiology*; D006801:Humans; D012815:Signal Processing, Computer-Assisted; D014732:Vibration