What finding may indicate choanal atresia in a term infant?

In an infant with choanal atresia, the condition involves the blockage of the nasal passage, which can severely impact breathing. The inability to pass a nasogastric tube down either nare serves as a significant clinical indicator of this congenital anomaly. This finding suggests that the nasal passages are obstructed and may not allow for normal air passage, which is crucial for adequate breathing and feeding in neonates. Normally, a nasogastric tube should easily pass through the nasal passages into the esophagus; if it cannot, it raises suspicion for choanal atresia.

Other findings, such as rapid breathing, persistent cough, or abnormal lung sounds, may exist in various respiratory conditions but are not specific to choanal atresia. These signs could indicate other issues but do not provide the direct evidence of blocked nasal passages that the inability to pass a nasogastric tube does. Thus, the specific inability to pass a nasogastric tube directly highlights the underlying anatomical obstruction characteristic of choanal atresia.