1137 Effects of parity and mid-gestation nutrient restriction on umbilical blood flow, fetal and placental measurements, and birth weight in sheep

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 545-546
Author(s):  
M. A. Vasquez ◽  
K. C. Swanson ◽  
K. A. Vonnahme
1982 ◽  
Vol 242 (3) ◽  
pp. H429-H436 ◽  
Author(s):  
R. B. Wilkening ◽  
S. Anderson ◽  
L. Martensson ◽  
G. Meschia

The effect of variations of uterine blood flow (F) on placental transfer was examined in six chronic sheep preparations by measuring the placental clearances of ethanol (CE) and antipyrine (CA) at different levels of F. Norepinephrine infusion, hemorrhage, and occlusion of the terminal aorta were used to reduce F below normal. The reduction of F had no appreciable effect on umbilical blood flow (f). In each ewe, CE significantly correlated with F. The CE vs. F relationship at constant f was curvilinear with convexity toward the clearance axis. Regression analysis showed that the equation 1/CE = 1/.911 F + 1/.831 f could account for most of the CE variance (r2 = 0.97). Implicit in this relation is the concept that, given a certain level of placental perfusion, an F/f ratio congruent to 1 is optimal for the exchange of highly diffusible inert molecules between mother and fetus [CE/(F + f) was maximum at F/f = 0.955]. CA was not significantly different from CE at low clearance level but became smaller than CE at clearance values greater than 300 ml/min. This suggests that a high rates of perfusion placental permeability was a factor in limiting CA.


2021 ◽  
Vol 22 (15) ◽  
pp. 8150
Author(s):  
Amelia R. Tanner ◽  
Cameron S. Lynch ◽  
Victoria C. Kennedy ◽  
Asghar Ali ◽  
Quinton A. Winger ◽  
...  

Deficiency of the placental hormone chorionic somatomammotropin (CSH) can lead to the development of intrauterine growth restriction (IUGR). To gain insight into the physiological consequences of CSH RNA interference (RNAi), the trophectoderm of hatched blastocysts (nine days of gestational age; dGA) was infected with a lentivirus expressing either a scrambled control or CSH-specific shRNA, prior to transfer into synchronized recipient sheep. At 90 dGA, umbilical hemodynamics and fetal measurements were assessed by Doppler ultrasonography. At 120 dGA, pregnancies were fitted with vascular catheters to undergo steady-state metabolic studies with the 3H2O transplacental diffusion technique at 130 dGA. Nutrient uptake rates were determined and tissues were subsequently harvested at necropsy. CSH RNAi reduced (p ≤ 0.05) both fetal and uterine weights as well as umbilical blood flow (mL/min). This ultimately resulted in reduced (p ≤ 0.01) umbilical IGF1 concentrations, as well as reduced umbilical nutrient uptakes (p ≤ 0.05) in CSH RNAi pregnancies. CSH RNAi also reduced (p ≤ 0.05) uterine nutrient uptakes as well as uteroplacental glucose utilization. These data suggest that CSH is necessary to facilitate adequate blood flow for the uptake of oxygen, oxidative substrates, and hormones essential to support fetal and uterine growth.


2003 ◽  
Vol 189 (6) ◽  
pp. S218
Author(s):  
Zeev Weiner ◽  
Rula Hamisa ◽  
Allan Fisher ◽  
Allan Bombard ◽  
Eliezer Shalev

Neonatology ◽  
1978 ◽  
Vol 33 (5-6) ◽  
pp. 225-235 ◽  
Author(s):  
William Berman jr. ◽  
Robert C. Goodlin ◽  
Michael A. Heymann ◽  
Abraham M. Rudolph

1987 ◽  
Vol 15 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Léon G. M. Mulders ◽  
Pieter F. F. Wijn ◽  
Henk W. Jongsma ◽  
Peter R. Hein

1986 ◽  
Vol 65 (Supplement 3A) ◽  
pp. A378
Author(s):  
G. F. Marx ◽  
M. Schuss ◽  
A. Anyaegbunam ◽  
A. Fleischer

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