Oxyhemoglobin dissociation characteristics of human and sheep maternal and fetal blood

Abstract 1.1. Oxyhemoglobin dissociation curves were obtained from in vivo studies of maternal, fetal and neonatal sheep blood. Similar studies using slightly different techniques were performed on human maternal and fetal blood. 2.2. In the sheep, the in vivo analysis results in oxygen dissociation curves that are shifted to the left of those reported by others. The fetal curves lie to the left of maternal with the neonatal in between. In the human, the fetal curve is shifted to the right and is not significantly different from the maternal curve. 3.3. Oxyhemoglobin dissociation characteristics are probably influenced by the use of metabolic antagonists and by the passage of time required for analysis of the blood. These factors may alter the ionic distribution between plasma and erythrocytes and, hence, affect the oxygen affinity of the blood.