The effect of behavioral states on fetal heart rate and middle cerebral artery flow-velocity waveforms in normal full-term fetuses.
OBJECTIVE
To evaluate the effect of fetal behavioral states on the relationship between fetal heart rate (FHR) and middle cerebral artery resistance index (MCA RI) in normal fetuses.


METHODS
The FHR and MCA RI of 10 normal cases from 37 to 40 weeks of gestation were recorded consecutively over a 45-min period. Correlations between the MCA RI and FHR during resting and active phases, classified by an actocardiotocogram, were analyzed by simple regression analysis.


RESULTS
The mean FHR and MCA RI were significantly higher during the active phase (140.3 +/- 6.6 bpm, 0.79 +/- 0.06) than those during the resting phase (137.4 +/- 6.8 bpm, 0.75 +/- 0.07, P < 0.01, two sample t-test). There was a significant negative correlation (r = - 0.22, n = 2642, P < 0.01) between RI and FHR during the active phase and a significant positive correlation (r = 0.28, n = 2066, P < 0.001) during the resting phase.


CONCLUSIONS
The relationship between FHR and the MCA RI during the resting phase is different from during the active phase.
Shono
M
M
Department of Obstetrics and Gynecology, Saga Medical School, Japan.
Shono
H
H
Ito
Y
Y
Muro
M
M
Uchiyama
A
A
Sugimori
H
H
D001519:Behavior / Q000502:physiology; D001783:Blood Flow Velocity; D002536:Cerebral Arteries / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D005333:Fetus / Q000502:physiology*; D005865:Gestational Age; D006340:Heart Rate, Fetal; D006801:Humans; D011247:Pregnancy; D012044:Regression Analysis; D018608:Ultrasonography, Doppler; D014655:Vascular Resistance