The cause of choanal atresia is unknown, but is thought to result from persistence of the membrane between the nasal and oral spaces during fetal development. The condition is the most common nasal abnormality seen in the newborn infant, affecting about 1 in 7,000 live births. Choanal atresia may be either on one side or on both sides and is often associated (in about 50% of cases) with other congenital abnormalities.

The newborn is what is known as an "obligate nose breather," meaning it must breathe through its nose because its oral airway is not yet developed enough to allow for frequent mouth breathing. In fact, almost the only time an infant does not breathe through its nose is when crying.

Choanal atresia blocking both sides (bilateral) of the nose causes acute breathing problems with cyanosis and breathing failure. Infants with bilateral choanal atresia may need resuscitation at delivery.

Blockage on only one side causes less severe problems. Choanal atresia is generally recognized shortly after birth while the infant is still in the hospital.

• difficulty breathing following birth, which may result in cyanosis (bluish discoloration), unless infant is crying
• inability to nurse and breathe at same time
• marked retraction of chest unless breathing through mouth or crying
• nurse is unable to pass a catheter through each side of the nose into the throat
• persistent one-sided nasal blockage or discharge may be a sign of choanal atresia affecting that side

• A physical examination may show an obstruction of the nose.
• The inability to pass a catheter through one or both sides of the nose into the back of the throat strongly suggests a nasal obstruction.
• Instilling an x-ray dye in the nasal cavity and taking an x-ray can also be used to diagnose choanal atresia.
• A fiberoptic endoscope may be used to see the blockage.
• CT may be performed.

The immediate concern is to resuscitate the baby if necessary. An airway may need to be placed so that the infant can breathe. In some cases, intubation or tracheostomy may be needed.

An infant can learn to mouth breathe, which can delay the need for immediate surgery.

Surgery to remove the obstruction cures the problem. It may be delayed if the infant can tolerate mouth breathing. Possible surgical approaches include through the nose (transnasal) and through the mouth (transpalatal).

• respiratory arrest (the infant stops breathing altogether)
• aspiration while feeding and attempting to breathe through the mouth
• after surgery, narrowing of the area can recur (restenosis) and require dilation or reoperation