What changes occur in respiration during pregnancy?

During pregnancy, there are several physiological changes that occur in the body, including those related to the respiratory system. One notable change is an increase in the rate of respiration. This increase, typically by 1-2 breaths per minute, is primarily due to several factors: the growing uterus pushes up against the diaphragm, leading to a reduced lung volume, and the increased metabolic demands of the mother and growing fetus necessitate more efficient gas exchange.

Moreover, hormonal changes, particularly an increase in progesterone, stimulate the respiratory center in the brain, causing an increase in tidal volume (the amount of air inhaled and exhaled) and influencing the overall respiratory rate. The body adapts to these changes to ensure that there is enough oxygen supplied to both the mother and the fetus, making the increase in respiratory rate a key physiological adjustment during pregnancy.

This is why the correct answer indicates that respiration increases by 1-2 breaths per minute during this period.