Effect of Maternal Intravenous Infusions on Fetal Extracellular Fluid Composition in Pregnant Ewes

Abstract

Infusion of intravenous solutions to women in labor is common clinical practice. Since these infusions may change the volume and electrolyte balance between the mother and fetus, we investigated the influence of acute maternal volume expansion upon fetal and maternal fluid and electrolyte equilibrium in the chronically catheterized fetal lamb. Paired measurements of maternal and fetal plasma sodium and potassium concentrations, osmolality, and colloid osmotic pressure (COP), plus measurements in the fetal-placental plasma volume were obtained following rapid maternal infusions with saline, dextrose, and dextran solutions. Maternal infusions resulted in changes in fetal electrolyte concentrations as well as alterations in transplacental COP differences. Despite these changes, however, no changes in fetal plasma volume were noted.

Colloid osmotic pressure after hemorrhage and replenishment with Oxyglobin Solution, hetastarch, or whole blood in pregnant sheep

“…2000). This value is still well in excess of the maternal plasma COP before hemorrhage for the sheep in this study (approximately 20 mm Hg) and previously reported normal values (Golden et al. 1985; Layon & Gallagher 1987).…”

“…In sheep, during late gestation (128–133 days), maternal COP is usually 6 mm Hg greater than fetal COP (Golden et al. 1985).…”

“…Oxyglobin Solution has a higher in vitro COP (43 mm Hg)(Chan et al. 2000) than hetastarch (31 mm Hg)(Haupt & Rackow 1982) or ovine plasma (20 mm Hg) (Golden et al. 1985).…”