Which description best fits the thoracic cage during pregnancy?

• A. It becomes narrower
• B. It may appear wider
• C. It remains the same
• D. It collapses

Answer: (B)

During pregnancy the thoracic cavity adapts to meet increased respiratory demands. The growing uterus elevates the diaphragm, reducing the vertical space, while hormonal changes loosen the ligaments around the ribs. This allows the rib cage to flare outward, so the chest circumference often increases and the thorax can appear wider. This widening helps maintain ventilation as oxygen needs rise. So the description that the thoracic cage may appear wider best captures these physiological changes. The other options don’t fit the expected adaptation: the chest doesn’t narrow or collapse, and it doesn’t stay exactly the same.