O2 delivery to fetus in labor

Obstetric Anesthesia

Fetal stress responses to decreased DO2 includes bradycardia (2/2 vagal activity), increased alpha adrenergic activity, redistribution of blood (from splanchnic bed to heart, brain, placenta, adrenals), decrease in ventricular output, and decreased fetal breathing movements.

Fetal DO2

  • Uterine Blood Flow: modifiable – increase cardiac output, minimize alpha activity
  • Maternal Hemoglobin: modifiable (transfusion)
  • % Saturation (maternal): modifiable (Ensure maternal SpO2 100%). Note that supranormal PaO2 does not seem to affect fetal SvO2 [see Figure 12-6 in Datta].


Answered correctly


Year asked