Which of the following is true regarding the changes in lung mechanics during pregnancy?

During pregnancy, one of the key changes in lung mechanics is the reduction in residual volume. As the uterus expands, it exerts upward pressure on the diaphragm, which causes it to be positioned higher in the thoracic cavity compared to its position in the non-pregnant state. This elevated diaphragm, along with the anatomical and physiological changes that occur, leads to a decrease in residual volume.

As pregnancy progresses, several other changes in lung function and mechanics are observed, including an increase in tidal volume and a decrease in functional residual capacity. The increase in tidal volume is a compensatory response to ensure adequate oxygenation for both the mother and the developing fetus. However, the residual volume, which is the volume of air remaining in the lungs after a maximal exhalation, decreases due to the upward displacement of the diaphragm.

Furthermore, changes during pregnancy can also involve variations in minute ventilation and the respiratory rate, both of which adjust to maintain optimal oxygen levels. Thus, the understanding of how lung mechanics change during pregnancy highlights the significant physiological adaptations that occur to support both maternal and fetal health.