Variable fetal heart rate decelerations and electrocortical activities.
OBJECTIVE
The purpose of this study was to examine the influence of fetal behavioral states on baroreflex-mediated, variable fetal heart rate decelerations caused by umbilical cord occlusion.


METHODS
Five chronically instrumented fetal lambs were subjected to intermittent partial umbilical cord occlusion for 1 minute every 3 minutes, lasting 2 hours. Fetal behavioral states determined by electrocorticogram and heart rates by electrocardiogram were monitored continuously during these experiments.


RESULTS
The fetuses exhibited an alteration between low- and high-voltage electrocorticogram states. Both the depth and width of the variable fetal heart rate decelerations were greater during high-voltage than during low-voltage electrocorticogram.


CONCLUSIONS
Amplitude and duration of variable fetal heart rate decelerations are affected by fetal behavioral states.
Murata
Y
Y
Department of Obstetrics and Gynecology, University of California, Irvine, School of Medicine, Orange, California.
Quilligan
E J
EJ
Ninomiya
Y
Y
Wakatsuki
A
A
Masaoka
N
N
Oka
S
S
Fujimori
K
K
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D002245:Carbon Dioxide / Q000097:blood; D003250:Constriction; D004569:Electroencephalography; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006340:Heart Rate, Fetal / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D010100:Oxygen / Q000097:blood; D011247:Pregnancy; D012756:Sheep; D014470:Umbilical Cord
D002245:Carbon Dioxide; D010100:Oxygen