During pregnancy, which change is expected regarding the woman's blood volume?

During pregnancy, it is normal for a woman to experience an increase in plasma volume, which is a crucial physiological adaptation. This increase can be attributed to several factors that support both the mother and the developing fetus.

The plasma volume expands significantly - by about 40-50% during pregnancy. This increase serves several purposes: it supports the increased metabolic demands of both the mother and the fetus, helps protect against potential blood loss during delivery, and plays a role in ensuring adequate placental perfusion.

While there is also an increase in red blood cell mass during pregnancy, this does not occur at the same rate as the increase in plasma volume. As a result, pregnant women can sometimes experience a dilutional anemia, where the increase in plasma dilutes the concentration of red blood cells. The body’s adjustments in blood volume are part of a complex system that ensures optimal nutrient and oxygen delivery to the fetus throughout the pregnancy.

The other options do not accurately reflect the physiological changes that occur during pregnancy. There is indeed a notable increase in both blood volume and its components, but focusing specifically on plasma volume allows for a clearer understanding of one of the key modifications that occur to support pregnancy.