Until about three months of age, how do infants primarily breathe?

• A. Breath through mouth
• B. Breath through nose
• C. Diaphragm breathing
• D. Chest breathing

Answer: (B)

Infants are obligate nasal breathers for the first few months of life. The nose is the preferred route for air because nasal breathing provides humidified, filtered air and supports safe feeding, since the airway is arranged to coordinate breathing with swallowing. The mouth remains mainly for feeding during this early period, so breathing primarily through the nose helps reduce the risk of aspiration and keeps air flowing efficiently while the baby matures. As infants grow, nasal passages can still be used, but mouth breathing becomes more common later, especially when nasal congestion or crying occurs. The mechanism of breathing in infants often uses the diaphragm (belly breathing) due to the underdeveloped chest wall muscles, but the question focuses on the route of breathing, which is nasal.