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