What is a normal nose in a newborn?

Normal Nose in a Newborn

A normal newborn nose should allow passage of a catheter through both nostrils into the pharynx, with the infant breathing comfortably through the nose during quiet periods, as newborns are obligate nasal breathers during the first 3-4 weeks of life. 1, 2

Anatomical and Functional Characteristics

Nasal Breathing Physiology

• Newborns are obligate nasal breathers between 2-6 months of age, making nasal patency critical for survival 3, 1, 2
• The nasal passages contribute approximately 50% of total airway resistance in newborns 3
• Complete or partial nasal obstruction in infants below 2-6 months can lead to fatal airway obstruction because they cannot effectively compensate by mouth breathing 3
• Even minor increases in nasal congestion, such as from a simple upper respiratory infection, can create near-total obstruction 3

Normal Nasal Patency Assessment

• The definitive test for normal nasal anatomy is the ability to pass a catheter through each nostril into the pharynx 1
• Inability to pass a catheter bilaterally indicates bilateral choanal atresia, which requires immediate airway management 1
• Normal newborns should not exhibit periodic respiratory distress and cyanosis that is relieved only by crying 1

Key Clinical Features of a Normal Newborn Nose

Expected Findings

• Both nostrils patent with free airflow 1, 4
• No significant nasal flaring or retractions during quiet breathing 4
• Ability to feed without severe respiratory distress or aspiration 1
• No persistent mouth breathing in the first weeks of life 1, 2

Normal Variations

• Minor nasal congestion from physiologic rhinitis is common and typically does not cause severe obstruction 3
• Transient sneezing and mild nasal secretions are normal 4
• The nasal bridge may appear flat or wide, which is a normal ethnic and developmental variation 5

Critical Red Flags Requiring Immediate Evaluation

Life-Threatening Obstruction

• Bilateral choanal atresia presents immediately after birth with periodic respiratory distress and cyanosis relieved by crying 1
• These infants require oropharyngeal airway or intubation within the first hours of life 1
• Do not delay surgical intervention—immediate airway management is required within hours, with surgical correction planned within the first days of life 1

Associated Abnormalities

• Bilateral choanal atresia has associated congenital abnormalities in 50% of cases (up to 75% in bilateral presentations) 1, 6
• CHARGE syndrome is the most frequent association (20% of cases), requiring evaluation for Coloboma, Heart defects, Choanal Atresia, Retardation, Genito-urinary abnormalities, and Ear defects 1, 6

Common Pitfalls to Avoid

• Do not assume an infant can compensate for nasal obstruction by mouth breathing in the first 3-4 weeks of life—they are obligate nasal breathers and cannot effectively switch 1, 2
• Do not attribute severe feeding difficulties solely to behavioral issues without assessing nasal patency 1
• Do not overlook the possibility of unilateral choanal atresia, which may present more subtly than bilateral cases but still requires evaluation 1, 6
• Do not delay diagnostic evaluation if a catheter cannot be passed through the nostrils—this requires immediate endoscopic examination and CT imaging 1