Infants are primarily considered to be what type of breathers until around 4 months of age?

Infants are primarily considered to be nose breathers until around 4 months of age because their anatomy and physiology are adapted for this mode of breathing. At birth, the nasal passages are more developed than the oral cavity, which allows infants to breathe effectively through their noses, even while feeding. This feature is particularly important, as it enables them to both breathe and suckle simultaneously.

Nose breathing also assists in humidifying and filtering the air before it reaches the lungs, which is crucial for their developing respiratory system. The ability to breathe through the nose helps ensure adequate oxygenation while minimizing the risk of respiratory infections. As the infant grows and their oral cavity develops, they begin to incorporate mouth breathing, but this transition typically occurs around the age of 4 months.