RESUMEN
Congenital nasal aperture stenosis is an unusual cause of upper airway obstruction among neonates, and rarely presents as unilateral. Most commonly presents as choanal atresia. A CT evaluation is essential to confirm the diagnosis. Both surgical and conservative management can be applied, based on the severity of the associated clinical presentation; however, the very rare unilateral condition is usually treated conservatively. We present a case of a 30-day-old male baby [second twin, preterm 29 weeks pregnancy, and birth weight 1.070 kg] with difficult breathing since birth. The baby was referred for an ENT consultation. He was on a nasal cannula, not in respiratory distress, with no stridor, nor tachypnea. There were decreased breathing sounds in the left nostril. Nasogastric tubes size 8 French [Fr] and 6 Fr could not be introduced through the left nostril, which looked obstructed more anteriorly