A 2-day-old term newborn born to non-consanguineous parents presents with severe respiratory distress, cyanosis, and poor feeding. The clinical team notes that the infant's cyanosis and distress IMPROVE markedly when the baby cries. The condition marked **A** in the diagram represents this paradoxical presentation. Which of the following is the MOST LIKELY diagnosis and the FIRST-LINE bedside diagnostic maneuver?

Explanation

## Why Option 1 is correct Bilateral choanal atresia is a congenital obstruction of the posterior nasal aperture (bony ~90%, membranous ~10%) that presents as a neonatal emergency in the first days of life. Newborns are obligate nasal breathers for the first 4–6 weeks; therefore, bilateral obstruction causes severe respiratory distress and cyanosis at rest. The PARADOXICAL IMPROVEMENT with crying is pathognomonic: when the infant cries, the mouth opens and the oral airway becomes patent, bypassing the nasal obstruction. The first-line bedside diagnostic test is the inability to pass a soft 6-French catheter through either naris into the oropharynx—this simple maneuver confirms the diagnosis at the bedside before imaging. Definitive diagnosis is confirmed by CT scan (bony vs. membranous, unilateral vs. bilateral) and fiberoptic nasal endoscopy. The clinical presentation in **A**—respiratory distress with quiet breathing that improves with crying—is the classic hallmark of bilateral choanal atresia (Nelson 21e Ch 410; Dhingra ENT 7e). ## Why each distractor is wrong - **Option 2 (Laryngomalacia)**: While laryngomalacia is the most common cause of stridor in newborns, it presents with inspiratory stridor (not cyanosis at rest), and the distress typically WORSENS with agitation and crying, not improves. The omega-shaped epiglottis is seen on laryngoscopy, not detected by inability to pass a catheter through the nares. - **Option 3 (Tracheoesophageal fistula)**: TEF presents with excessive drooling, choking with first feeding, and recurrent pneumonia—not with the cyclical cyanosis pattern described. The nasogastric tube would coil in the proximal esophagus (not pass into the stomach), but this is not the first-line bedside test for the presentation shown in **A**. - **Option 4 (Posterior laryngeal cleft)**: Laryngeal cleft causes aspiration, stridor, and feeding difficulty, but NOT the paradoxical improvement with crying. The distress does not improve when the mouth opens; instead, it worsens with feeding and aspiration risk. **High-Yield:** Bilateral choanal atresia = obligate nasal breather + posterior nasal obstruction = respiratory distress at rest that PARADOXICALLY IMPROVES with crying (oral airway patent). First bedside test: soft catheter cannot pass through either naris. [cite: Nelson 21e Ch 410; Dhingra ENT 7e]