O2 delivery to fetus in labor
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.
- 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].