What effect does pregnancy have on tidal volume?

During pregnancy, the physiological changes a woman's body undergoes lead to an increase in tidal volume, which is the amount of air breathed in and out at rest. As the pregnancy progresses, there is an increase in metabolic demand for both the mother and the developing fetus, which necessitates greater oxygen intake.

The increase in tidal volume can be attributed to several factors including hormonal changes, which promote relaxation of the respiratory muscles, and the expanding uterus that pushes the diaphragm upward. These changes enhance the efficiency of oxygen exchange and help meet the increased oxygen requirements.

An increase of approximately 40% is generally observed in tidal volume during pregnancy, reflecting the body’s adaptation to ensure sufficient oxygen delivery to both the mother and the fetus. This adjustment is crucial for supporting fetal development and accommodating the mother’s increased metabolic workload.