The effect of acute maternal hypoxia on fetal oxygenation and the umbilical circulation in the sheep.
The mean oxygen consumption was 8.4 +/- 1.9 ml/min/kg in the near-term fetal sheep. In response to acute maternal hypoxia fetal O2 consumption decreased to lower than 50% of the control values. The decrease was rapidly instituted, proportional to the degree of hypoxia, sustained for up to 47 min and stable over this period. With increasing duration of hypoxia, a progressive metabolic acidosis developed. Recovery of oxygen consumption occurred rapidly after hypoxia ceased, though the acidosis was not resolved until 2 h later. Umbilical blood flow was maintained during maternal hypoxia and umbilical arterial and venous pressures increased. A fetal bradycardia invariably accompanied the hypoxia.
D000136:Acid-Base Equilibrium; D000818:Animals; D001769:Blood; D001794:Blood Pressure; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D005333:Fetus / Q000502:physiology*; D006339:Heart Rate; D006863:Hydrogen-Ion Concentration; D000860:Hypoxia / Q000150:complications*; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption; D010313:Partial Pressure; D011247:Pregnancy; D012039:Regional Blood Flow; D012756:Sheep; D014469:Umbilical Arteries / Q000503:physiopathology*; D014471:Umbilical Veins / Q000503:physiopathology*
D002245:Carbon Dioxide; D010100:Oxygen