What changes occur in respiratory patterns during pregnancy?

• A. Deeper respirations
• B. Shallow respirations
• C. No change
• D. Irregular breathing

Answer: (A)

During pregnancy the breathing pattern shifts mainly toward deeper breaths rather than faster ones. Progesterone increases the sensitivity of the respiratory center to carbon dioxide, boosting tidal volume so each breath moves more air. As a result, minute ventilation rises substantially even though the breathing rate stays about the same or increases only slightly. The enlarging uterus also pushes the diaphragm upward, reducing functional residual capacity, so the body relies on deeper breaths to improve oxygen uptake for both mother and fetus. This increased ventilation creates a mild respiratory alkalosis, which the kidneys compensate for over time by excreting bicarbonate.