SUPPLY OF O2 TO PRIMATE FETUS WITH 2 DIFFERENT 02 TENSIONS AND ANESTHETICS

Umbilical blood flows and fetal oxygen uptakes were measured in 18 pregnant Macaca mulatta monkeys at maternal arterial O2 tensions of 107 mm Hg ± 14 mm Hg. The average umbilical blood flow was 212 cc.min-1.kg-1 and the average fetal oxygen consumption was 7.73 cc.min-1.kg-1. In 8 of these animals the average uterine blood flow was 213 cc.min-1.kg-1 and the average uterine oxygen uptake was 10.85 cc.min-1.kg-1. Seventy-four per cent (8.02 cc.min-1.kg-1) of this oxygen was taken up by the fetus and 26% (2.83 cc.min-1.kg-1 by the uteroplacental tissue. Elevated maternal arterial PO2 tensions (257 ± 59) did not result in a statistically significant increase or decrease in the umbilical or uterine blood flows or oxygen uptake in nonasphyxiated primate fetuses. The oxygen tension in the fetal umbilical vein increased significantly (P < 0.025). The results were similar under anesthesia with either halothane or succinylcholine. © 1969.