Meloxicam effectively inhibits preterm labor uterine contractions in a chronically catheterized pregnant sheep model: Impact on fetal blood flow and fetal-maternal physiologic parameters

2006 ◽  
Vol 195 (2) ◽  
pp. 528-534 ◽  
Author(s):  
Valeria E. Rac ◽  
Charlene Small ◽  
Catherine A. Scott ◽  
S. Lee Adamson ◽  
Dan Rurak ◽  
...  
Keyword(s):  
Blood Flow ◽  
Preterm Labor ◽  
Fetal Blood ◽  
Sheep Model ◽  
Uterine Contractions ◽  
Pregnant Sheep ◽  
Physiologic Parameters

Maternal and fetal blood flow velocity waveforms in patients with preterm labor: Prediction of successful tocolysis.

1988 ◽  
Vol 159 (4) ◽  
pp. 947-950 ◽  
Author(s):  
Harbinder S. Brar ◽  
Arnold L. Medearis ◽  
Greggory R. DeVore ◽  
Lawrence D. Platt
Keyword(s):  
Blood Flow ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Preterm Labor ◽  
Fetal Blood

Measurement of Uterine Blood Flow and Uterine Metabolism

1958 ◽  
Vol 195 (3) ◽  
pp. 614-620 ◽  
Author(s):  
N. S. Assali ◽  
K. Dasgupta ◽  
A. Kolin ◽  
L. Holms
Keyword(s):  
Blood Flow ◽  
Uterine Contraction ◽  
Uterine Blood Flow ◽  
Progressive Decrease ◽  
Flow Meter ◽  
Induced Labor ◽  
Uterine Contractions ◽  
Uterine Involution ◽  
Pregnant Sheep

Uterine blood flow has been measured with a chronically implanted miniature electromegnetic flow meter in unanesthetized pregnant sheep and dogs during spontaneous and oxytocin induced labor and followed in the same animal for several postpartum days. In either spontaneous or oxytocin induced labor, uterine contractions are accompanied by a significant decrease in uterine blood flow and relaxations by the return of the flow to or higher than control values. The decrease is roughly proportional to the intensity of uterine contraction. When the contraction is of a tetanic nature and not followed by relaxation, uterine ischemia is so severe that the fetus might succumb. After the delivery of the fetus and before the expulsion of the placenta, uterine blood flow falls slightly. However, after separation and expulsion of the placenta, uterine blood flow falls precipitously. Thereafter, a very slight and progressive decrease continues for several days paralleling uterine involution.

Maternal and fetal blood flow velocity waveforms in patients with preterm labor: Relationship to outcome

1989 ◽  
Vol 161 (6) ◽  
pp. 1519-1522 ◽  
Author(s):  
Harbinder S. Brar ◽  
Arnold L. Medearis ◽  
Greggory R. DeVore ◽  
Lawrence D. Platt
Keyword(s):  
Blood Flow ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Preterm Labor ◽  
Fetal Blood ◽  
Labor Relationship

Regional blood flow and vascular resistance in response to oxytocin in the pregnant sheep and dog

1961 ◽  
Vol 16 (6) ◽  
pp. 1087-1092 ◽  
Author(s):  
N. S. Assali ◽  
L. Holm ◽  
H. Parker
Keyword(s):  
Blood Flow ◽  
Vascular Resistance ◽  
Regional Blood Flow ◽  
Uterine Blood Flow ◽  
Pregnant Uterus ◽  
Blood Flows ◽  
Uterine Contractions ◽  
Intravenous Drip ◽  
Pregnant Sheep ◽  
Regional Vascular Resistance

The effects of oxytocin on regional blood flow and regional vascular resistance were investigated in a group of pregnant ewes and bitches not in labor and in another group in early labor. Single injections or intravenous drip infusion did not change significantly arterial pressure, cardiac output, electrocardiogram, and renal, iliac, femoral, and carotid blood flows in any of the animals studied. The effects on the pregnant uterus were negligible before the onset of spontaneous labor. Only when the animal was in labor did oxytocin produce an increase in uterine contractions accompanied by a significant decrease in uterine blood flow. The data indicate that in the pregnant sheep and dog the circulatory action of oxytocin is limited to the pregnant uterus in labor and that the decrease in blood flow is probably due to an increase in intramural vascular resistance caused by the contracting myometrium around the uterine arterioles. Submitted on May 5, 1961

Transplacental Transfer and Fetal Pharmacodynamics of Sildenafil in the Pregnant Sheep Model

2021 ◽  
pp. 1-10
Author(s):  
Felix Rafael De Bie ◽  
Dyuti Sharma ◽  
Damien Lannoy ◽  
Karel Allegaert ◽  
Laurent Storme ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Pulmonary Blood Flow ◽  
Uterine Artery ◽  
Blood Gases ◽  
Gas Analysis ◽  
Sheep Model ◽  
Transplacental Transfer ◽  
Pregnant Sheep ◽  
Dose Dependent

<b><i>Background:</i></b> Sildenafil is a phosphodiesterase-5 inhibitor considered for antenatal use for a variety of indications. We sought to assess sildenafil pharmacokinetics in the pregnant ewe and fetus and evaluate its physiological fetal effects. <b><i>Methods:</i></b> Twelve fetal lambs (127–133 days GA, term 145) were chronically catheterized in utero. Ewes received different doses of sildenafil, either via subcutaneous injection (1.6, 2.0 mg/kg/day) or intravenous (IV) infusion (3, 5, 7, 10, and 12 mg/kg/day). Maternal and fetal sildenafil concentrations and metabolic status (blood gas analysis) were measured at given intervals. The fetal heart rate, pulmonary blood flow, systemic and aortic pressure, and maternal uterine artery pressure were continuously monitored. <b><i>Results:</i></b> The transplacental sildenafil transfer was 2.9% (range: 1.4–7.8%), preventing attainment of fetal target concentrations without toxic maternal levels. IV sildenafil infusion induced an immediate, temporary, dose-dependent reduction of pulmonary vascular resistance (38–78%) and increased both pulmonary blood flow (32–132%) and heart rate (13–49%), with limited nonlinear dose-dependent effects on systemic and pulmonary pressures. Fetal and maternal blood gases and maternal uterine artery pressures were unaffected by sildenafil infusion. <b><i>Conclusion:</i></b> In sheep, transplacental transfer of sildenafil is extremely low. Though, minimal fetal sildenafil concentrations induce an acute transient pulmonary vasodilation, well-tolerated by the fetus and ewe.

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