What is a common physical change noted during pregnancy?

During pregnancy, a notable physical change is the increase in heart rate. This change occurs as the body adapts to meet the increased metabolic demands of the developing fetus and the physiological changes associated with pregnancy. The heart works harder to supply blood, oxygen, and nutrients to both the mother and the growing baby, resulting in an elevated heart rate.

This increase in heart rate helps accommodate the higher blood volume that typically occurs during pregnancy, which supports circulation to the placenta and tissues. Increased heart rate is part of the body's overall adjustment to ensure that the mother can efficiently meet the needs of her changing body and the unborn child.

In contrast, the other options do not represent common physical changes associated with pregnancy. For example, body temperature may have minor fluctuations but doesn't consistently increase, and blood volume actually increases to support the developing fetus. Similarly, respiratory rate tends to increase rather than decrease as the body requires more oxygen intake.