Why does lung capacity increase by nearly 50% during pregnancy?

During pregnancy, lung capacity increases significantly to accommodate the growing needs of both the mother and the developing fetus. This increase is primarily due to two key physiological changes: each breath taken has a greater volume of air, often referred to as tidal volume, and there is a slight increase in the respiratory rate.

As pregnancy progresses, the body undergoes numerous adaptations. The diaphragm, which plays a crucial role in breathing, becomes more efficient and can move more freely due to changes in body position and hormone levels. This results in deeper breaths, allowing more air to enter and exit the lungs with each respiratory cycle.

Additionally, while the respiratory rate does see a mild increase, it is the increase in tidal volume that contributes significantly to the overall lung capacity being nearly 50% greater. This helps ensure that adequate oxygen is supplied to both the mother and the growing baby, supporting fetal development and meeting the heightened metabolic demands of the pregnant body.

By selecting this option, it encompasses the comprehensive changes affecting lung capacity during pregnancy, thereby highlighting how both the increase in the volume of each breath and the slight increase in breathing rate work together to enhance respiratory efficiency.