What causes physiological anemia in pregnant patients?

Physiological anemia in pregnant patients is primarily caused by hemodilution resulting from increased plasma volume. During pregnancy, there is a significant increase in the blood volume to support both the mother and the developing fetus. While the body does produce more red blood cells to accommodate the increased demand for oxygen, the increase in plasma volume is proportionally greater. This results in a dilution of red blood cells in the circulating blood, leading to a lower concentration of hemoglobin and hence the appearance of anemia, even though the absolute number of red blood cells might still be within a normal range.

This phenomenon is a normal adaptation during pregnancy and allows for enhanced perfusion and nutrient delivery to the placenta, facilitating fetal growth and development. Understanding this mechanism is crucial in differentiating between physiological anemia and anemia due to other causes, such as iron deficiency or blood loss, which require targeted interventions.