Shouldn't blood CO2 increase as resp rate remains same

In the video you had mentioned that there’s a decreased amt of air trapped in lungs but in notes it’s given increased. Also maam if decreased amt of air is trapped in lungs, shouldn’t blood CO2 increase as resp rate remains same …

Can you please clear my doubt maam??

Of physiological lung changes, functional residual capacity (FRC) decreases by approximately 20 to 30 percent or 400 to 700 mL during pregnancy.This capacity is composed of expiratory reserve volume—which drops 15 to 20 percent or 200 to 300 mL—and residual volume—which decreases 20 to 25 percent or 200 to 400 mL. FRC and residual volume decline progressively across pregnancy due to diaphragm elevation. Significant reductions are observed by the sixth month. Inspiratory capacity, the maximum volume that can be inhaled from FRC, rises by 5 to 10 percent or 200 to 350 mL during pregnancy. Total lung capacity—the combination of FRC and inspiratory capacity—is unchanged or decreases by less than 5 percent at term.

The respiratory rate is essentially unchanged, but tidal volume and resting minute ventilation increase significantly as pregnancy advances. The elevated minute ventilation is caused by several factors. These include enhanced respiratory drive primarily due to the stimulatory action of progesterone, low expiratory reserve volume, and compensated respiratory alkalosis. Thank you.