What changes occur in the respiratory system of a pregnant female patient?

During pregnancy, several physiological changes occur in the respiratory system to meet the increased metabolic demands of both the mother and the developing fetus. One significant change is that tidal volume increases by approximately 40 percent. Tidal volume refers to the amount of air inhaled or exhaled during normal breathing.

The increase in tidal volume helps to enhance the mother's oxygen intake, which is crucial as the body requires more oxygen to supply the growing fetus. This adjustment aids in improving ventilation and ensuring adequate gas exchange.

As pregnancy progresses, the diaphragm moves higher due to the expanding uterus, resulting in altered mechanics of breathing; however, the overall tidal volume increase helps counterbalance any potential limitations in lung capacity. Thus, the increase in tidal volume plays a vital role in accommodating the higher oxygen demands during pregnancy, making option B the correct answer.