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The heart rate deceleratory response in low‐risk human fetuses: Effect of stimulus intensity on response topography
Author(s) -
Groome Lynn J.,
Mooney Donna M.,
Holland Scherri B.,
Bentz Lynn S.,
Atterbury Jana L.,
Dykman Roscoe A.
Publication year - 1997
Publication title -
developmental psychobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 93
eISSN - 1098-2302
pISSN - 0012-1630
DOI - 10.1002/(sici)1098-2302(199703)30:2<103::aid-dev2>3.0.co;2-u
Subject(s) - stimulus (psychology) , heart rate , fetus , fetal heart rate , reflex , medicine , psychology , audiology , pregnancy , blood pressure , biology , psychotherapist , genetics
The purpose of this study was to determine the effect of stimulus intensity on heart rate response in 18 low‐risk human fetuses between 37 and 40 weeks gestation. Each fetus was stimulated in quiet sleep with a 30‐s voice sound at intensities of 80 dB and 90 dB. The fetal cardiac electrical signal was captured transabdominally at a rate of 1024 Hz and fetal R‐waves were extracted using adaptive signal‐processing techniques. We found that fetuses generally exhibited a 5‐ to 10‐s decrease in heart rate following stimulus onset at an intensity of 80 dB. The response pattern changed from deceleratory to acceleratory when stimulus intensity was increased to 90 dB. Our findings suggest that a heart rate deceleration at low‐stimulus intensity may be a component of the orienting reflex in the human fetus. © 1997 John Wiley & Sons, Inc. Dev Psychobiol 30: 103–113, 1997