Effect of fenoterol (Th1165a) infusion on uterine and umbilical blood flow in pregnant sheep

SUPPRESSION OF UTERINE CONTRACTIONS WITH ENOTEROL AND ITS EFFECT ON FETAL TcPo2 IN HUMAN TERM LABOUR

“…In the chronic sheep preparation, maternal infusion of fenoterol does give a marked rise in heart rate in the mother while fetal heart rate remains unchanged. Direct infusion of fenoterol into the fetus is followed by fetal tachycardia (Ehrenkranz et al, 1977~). The same results are described for ritodrine and salbutamol while the infusion of isoxsuprine into the mother gives a rise in maternal and fetal heart rate (Ehrenkranz et al, 19776).…”

Effect of continuous Infusion of fenoterol on maternal pelvic and fetal umbilical blood flow in pregnant sheep

“…EHRENKRANZ et al [7] and CHEZ et al [4] did not find any significant change in fetal heart rate, blood pressure or umbilical venous blood flow.…”

“…In several studies [1,9,11] increases in uterine blood flow were reported while other studies [2,3,4,6,7,8,10,12] showed no changes or even decreases in flow after betaadrenergic drug infusion. Part of these differences might be explained by the fact that different betasympathomimetic drugs were used, but more important seems the site of flow measurement in the pelvic vascular bed.…”

Isoxsuprine Infusion in the rat: Alterations in maternal, fetal and neonatal glucose homeostasis

“…The tocolytic properties of these agents are attributed to their 62 stimulatory effect which reduces the strength and frequency of contraction of uterine muscle. While much of the cardiovascular effects of these agents upon the mother and fetus has been identified [3,5,6,21], less is known about their effect upon glucose metabolism. Neonates delivered of women who received B sympathomimetic drugs are at increased risk of developing hyppglycemia [2,7].…”

“…Maternal and fetal hyperglycemia has been reported to develop with the administration of B sympathomimetics to women [18,26]. The increase in fetal glucose may be a direct drug effect upon the fetus äs suggested by the observation that fetal hyperglycemia develops during infusion of fenoterol directly to the sheep fetus [6]. EPSTEIN et al found elevated insulin concentrations in the cord plasma of infants whose mothers had received Bsympathomimetic agents and suggested that fetal hyperglycemia resulting in excessive insulin production might be responsible for neonatal hypoglycemia [7].…”