Heart Rate and PO2 in the Fetal Lamb

Information about fetal oxygenation in chronically catheterized animal subjects has previously depended on intermittent measurement of PO2 or O2 saturation in blood samples withdrawn from intravascular catheters. Recently, the performance and durability of implanted oxygen electrodes in both blood and tissue has improved. Thus, continuous monitoring of oxygen levels over many hours or days is now possible and we have previously reported (1) our experience with implantation of galvanic PO2 electrodes in fetal and maternal tissues in the pregnant ewe.