In summary:
| Heart rate | Increased (from 75 to 85-90) |
| Stroke volume | Increased (from 65ml to 80-90ml) |
| Cardiac output | Increased (from 5L/min to 7L/min) |
| Blood pressure | Decreased |
| Systemic vascular resistance | Decreased |
| Pulmonary vascular resistance | Decreased |
| Pulmonary artery wedge pressure | Unchanged |
| Blood volume | Increased by 50% |
| CVP | Unchanged |
| Colloid oncotic pressure | Decreased |
- Albumin and oncotic pressure decrease gradually thoughout pregnancy
- Oxygen consumption increases by 20% during pregnancy
- FRC decreases during pregnancy, due to compression of the diaphragm by the gravid uterus.
- Blood pressure decreases and is lowest in the second trimester
- Heart rate increases gradually thoughout pregnancy
- Stroke volume increases gradually thoughout pregnancy
- Cardiac output increases gradually thoughout pregnancy
- however, the IVC is compressed by the gravid uterus in the supine position, decreasing the preload
- Systemic vascular resistance decreases gradually thoughout pregnancy
- Total blood volume increases gradually during pregnancy
References
Chapter 64 (pp. 684) General obstetric emergencies by Winnie TP Wan and Tony Gin
Chapter 65 (pp. 692) Severe pre-existing disease in pregnancy by Jeremy P Campbell and Steve M Yentis
Thornburg, Kent L., et al. "Hemodynamic changes in pregnancy." Seminars in perinatology. Vol. 24. No. 1. WB Saunders, 2000.