Final answer:
A decrease in pulse pressure does not usually occur during pregnancy; instead, there is typically an increase in pulse pressure to support the growing fetus. Premature ventricular contractions and syncope can occur but are not as characteristic as increased pulse pressure. The correct option is c).
Step-by-step explanation:
The question posed is about physiological changes that do not usually occur during pregnancy. Out of the options listed, decrease in pulse pressure does not typically occur during pregnancy.
Pregnancy is usually associated with an increase in pulse pressure due to the higher cardiac output and relatively lower systemic vascular resistance to accommodate the growing fetus. Premature ventricular contractions (PVCs) may be observed on an electrocardiogram (ECG) but are not usually a cause for concern unless frequent and symptomatic.
Syncope (fainting) can also occur as it is related to postural and circulatory adjustments during pregnancy. Therefore, the correct answer is that a decrease in pulse pressure does not normally occur during pregnancy.
It is important to note that each pregnancy is unique, and some women may experience different symptoms or changes. Option c) is the correct one.