Maternal and fetal ethanol pharmacokinetics and cardiovascular responses in near-term pregnant sheep

1984 ◽  
Vol 62 (12) ◽  
pp. 1435-1439 ◽  
Author(s):  
M. E. Cumming ◽  
B. Y. Ong ◽  
J. G. Wade ◽  
D. S. Sitar
Keyword(s):  
Heart Rate ◽  
Fetal Heart Rate ◽  
Fetal Heart ◽  
Placental Transfer ◽  
Ethanol Concentration ◽  
Cardiovascular Responses ◽  
Maternal Circulation ◽  
Arterial Blood ◽  
Pregnant Sheep ◽  
Near Term

The disposition and cardiovascular effects of ethanol were studied in near-term pregnant sheep and their fetuses after intravenous infusions either to the mother or the fetus. Placental transfer of ethanol from mother to fetus was rapid, but transfer from the fetal to maternal circulation was impaired when ethanol was administered directly to the fetus. Plasma clearance of ethanol was similar from the mother and fetus in utero. In the maternal infusion experiments, both maternal and fetal heart rate increased with plasma ethanol concentration. However, in the fetal infusion experiments, fetal heart rate was inversely related to plasma ethanol concentrations while maternal mean arterial blood pressure increased with maternal plasma ethanol concentration. Further studies in neonatal lambs are needed to determine if ethanol has adverse effects on hemodynamics when the neonate is separated from its protective intrauterine environment.

scholarly journals Distance to Healthy Metabolic and Cardiovascular Dynamics From Fetal Heart Rate Scale-Dependent Features in Pregnant Sheep Model of Human Labor Predicts the Evolution of Acidemia and Cardiovascular Decompensation

2021 ◽  
Vol 9 ◽  
Author(s):  
Stephane G. Roux ◽  
Nicolas B. Garnier ◽  
Patrice Abry ◽  
Nathan Gold ◽  
Martin G. Frasch
Keyword(s):  
Heart Rate ◽  
Fetal Heart Rate ◽  
Fetal Heart ◽  
Temporal Dynamics ◽  
Sampling Rate ◽  
Well Being ◽  
Local Analysis ◽  
Arterial Blood ◽  
Pregnant Sheep ◽  
Human Labor

The overarching goal of the present work is to contribute to the understanding of the relations between fetal heart rate (FHR) temporal dynamics and the well-being of the fetus, notably in terms of predicting the evolution of lactate, pH and cardiovascular decompensation (CVD). It makes uses of an established animal model of human labor, where 14 near-term ovine fetuses subjected to umbilical cord occlusions (UCO) were instrumented to permit regular intermittent measurements of metabolites lactate and base excess, pH, and continuous recording of electrocardiogram (ECG) and systemic arterial blood pressure (to identify CVD) during UCO. ECG-derived FHR was digitized at the sampling rate of 1,000 Hz and resampled to 4 Hz, as used in clinical routine. We focused on four FHR variability features which are tunable to temporal scales of FHR dynamics, robustly computable from FHR sampled at 4 Hz and within short-time sliding windows, hence permitting a time-dependent, or local, analysis of FHR which helps dealing with signal noise. Results show the sensitivity of the proposed features for early detection of CVD, correlation to metabolites and pH, useful for early acidosis detection and the importance of coarse time scales (2.5–8 s) which are not disturbed by the low FHR sampling rate. Further, we introduce the performance of an individualized self-referencing metric of the distance to healthy state, based on a combination of the four features. We demonstrate that this novel metric, applied to clinically available FHR temporal dynamics alone, accurately predicts the time occurrence of CVD which heralds a clinically significant degradation of the fetal health reserve to tolerate the trial of labor.

scholarly journals Acute reduction of uterine blood flow and fetal heart rate changes in pregnant sheep near term

1977 ◽  
Vol 5 (1) ◽  
pp. 39-55 ◽  
Author(s):  
Heinz-Dieter Junge ◽  
Wolfgang Künzel ◽  
Friedrich Karl Klöck
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Fetal Heart Rate ◽  
Fetal Heart ◽  
Uterine Blood Flow ◽  
Pregnant Sheep ◽  
Near Term

Biphasic changes in fetal heart rate variability in preterm fetal sheep developing hypotension after acute on chronic lipopolysaccharide exposure

2014 ◽  
Vol 307 (4) ◽  
pp. R387-R395 ◽  
Author(s):  
Christopher A. Lear ◽  
Joanne O. Davidson ◽  
Lindsea C. Booth ◽  
Guido Wassink ◽  
Robert Galinsky ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Fetal Heart Rate ◽  
Low Dose ◽  
Fetal Heart ◽  
Transient Increase ◽  
Electromyographic Activity ◽  
Fetal Sheep ◽  
Arterial Blood ◽  
Fetal Heart Rate Variability

Perinatal exposure to infection is highly associated with adverse outcomes. Experimentally, acute, severe exposure to gram-negative bacterial lipopolysaccharide (LPS) is associated with increased fetal heart rate variability (FHRV). It is unknown whether FHRV is affected by subclinical infection with or without acute exacerbations. We therefore tested the hypothesis that FHRV would be associated with hypotension after acute on chronic exposure to LPS. Chronically instrumented fetal sheep at 0.7 gestation were exposed to a continuous low-dose LPS infusion ( n = 12, 100 ng/kg over 24 h, followed by 250 ng·kg−1·24 h−1 for a further 96 h) or the same volume of saline ( n = 10). Boluses of either 1 μg LPS or saline were given at 48, 72, and 96 h. Low-dose infusion was not associated with hemodynamic or FHRV changes. The first LPS bolus was associated with tachycardia and suppression of nuchal electromyographic activity in all fetuses. Seven of twelve fetuses developed hypotension (a fall in mean arterial blood pressure ≥5 mmHg). FHRV was transiently increased only at the onset of hypotension, in association with increased cytokine induction and electroencephalogram suppression. FHRV then fell before the nadir of hypotension, with transient suppression of short-term FHRV. After the second LPS bolus, the hypotension group showed a biphasic pattern of a transient increase in FHRV followed by more prolonged suppression. These findings suggest that infection-related hypotension in the preterm fetus mediates the transient increase in FHRV and that repeated exposure to LPS leads to progressive loss of FHRV.

Diurnal and other cyclic variations in human fetal heart rate near term

1982 ◽  
Vol 142 (5) ◽  
pp. 535-544 ◽  
Author(s):  
G.H.A. Visser ◽  
J.D.S. Goodman ◽  
D.H. Levine ◽  
G.S. Dawes
Keyword(s):  
Heart Rate ◽  
Fetal Heart Rate ◽  
Fetal Heart ◽  
Human Fetal Heart ◽  
Cyclic Variations ◽  
Near Term

Fetal blood volume, vascular pressure, and heart rate responses to fetal and maternal hyperosmolality

1986 ◽  
Vol 251 (4) ◽  
pp. H716-H721 ◽  
Author(s):  
L. L. Woods ◽  
R. A. Brace
Keyword(s):  
Heart Rate ◽  
Blood Volume ◽  
Intravenous Injection ◽  
Fetal Heart ◽  
Osmotic Dehydration ◽  
Venous Pressure ◽  
Cardiovascular Responses ◽  
Fetal Blood ◽  
Short Term ◽  
Pregnant Sheep

Our purpose was to explore the fetal cardiovascular responses to osmotic hydration or dehydration of the fetus. Chronically catheterized pregnant sheep with a single fetus, averaging 130 days gestation (term, 145-150 days), were studied. After an intravenous injection of 20 ml of 9% NaCl into the fetus (n = 6), fetal osmolality increased by a peak of 20 +/- 2 (SE) mosmol/kg and returned to control in 1.5-2 h. Fetal blood volume, mean arterial pressure, venous pressure, and heart rate increased by 17 +/- 4 ml, 5 +/- 1 mmHg, 3 +/- 1 mmHg, and 19 +/- 6 beats/min, respectively, at 2 min postinjection. These variables returned to normal within 20-60 min. After an intravenous injection of 240-300 ml of 9% NaCl into the ewe (n = 7), maternal osmolality increased by a peak of 48 +/- 4 mosmol/kg; fetal blood volume decreased by 36 +/- 6 ml, fetal vascular pressures were unchanged, and fetal heart rate decreased by 43 +/- 9 beats/min at 15 min postinjection. Fetal blood volume and heart rate returned to normal within 1 h even though fetal and maternal osmolalities were elevated by 20-25 mosmol/kg. With transplacental fluid movements in opposite directions following the fetal versus maternal hypertonic injections, these studies show that fetal blood volume is well regulated following osmotic hydration or dehydration, except for short-term transients lasting less than or equal to 1 h. Although fetal vascular pressures increased in parallel with blood volume following osmotic hydration, their lack of change following osmotic dehydration suggests a constriction of the fetal vasculature.(ABSTRACT TRUNCATED AT 250 WORDS)

Fetal Heart Rate Pattern in Term or Near-Term Cerebral Palsy: A Nationwide Cohort Study

2021 ◽  
Vol 76 (5) ◽  
pp. 261-263
Author(s):  
Masahiro Nakao ◽  
Asumi Okumura ◽  
Junichi Hasegawa ◽  
Satoshi Toyokawa ◽  
Kiyotake Ichizuka ◽  
...  
Keyword(s):  
Heart Rate ◽  
Cerebral Palsy ◽  
Cohort Study ◽  
Fetal Heart Rate ◽  
Fetal Heart ◽  
Fetal Heart Rate Pattern ◽  
Near Term ◽  
Heart Rate Pattern
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