Cardiovascular | Hematologic | Pulmonary |
Decreased SVR: In the 1st trimester progressively drops 35 - 40 percent hitting plateau in mid-2nd trimester | Plasma volume: Increases reaching peak at 30 - 34 weeks **Total intravascular volume increases ~50% | FRC: Decreases ~20% during 2nd half of pregnancy as a result of ERV & RV decrease |
Increased CO: Peaks in the early third trimester, HR increases ~25% from patient baseline | RBC mass: Increase starting 8 - 12 weeks and steadily continues to do so until the end of pregnancy, increasing by 20% - 30%. | Ventilation: Resting MV increases by nearly 50%, this results mainly from larger TV (~40% increase) while RR remains largely unchanged |
MAP: Remains fairly constant throughout pregnancy | Physiologic Anemia: Relative increase in plasma compared to RBC mass | Oxygen consumption: Increases approximately 20% |
Prothrombotic state: Increased prothrombotic factors including fibrinogen, factors II, VII, X, XII and VWF Decreased anticoagulant factors including protein S and reduced fibrinolysis via increased fibrinolytic inhibitors including thrombin activatable fibrinolytic inhibitor, PAI-1 and PAI-2 | **Minor changes with little clinical significance have been found in the following: VC, TLC, and diffusing capacity |