Prevalence:

• 1 in 50,000 births.

Ultrasound diagnosis:

• Agenesis or stenosis of a segment of the upper airways at the level of the trachea or larynx. In a few cases the condition results from the presence of laryngeal cysts or laryngeal web.
• Ultrasound features become evident ≥16 weeks’ gestation. The lungs are massively enlarged and hyperechogenic resulting in compression of the heart and development of ascites. The bronchial tree is dilated and the diaphragm inverted.

Associated abnormalities:

• The incidence of chromosomal abnormalities is not increased.
• Genetic syndromes are found in >50% of cases. The most common is Fraser syndrome (autosomal recessive; microphthalmia, facial cleft, tracheal atresia, bilateral renal agenesis, heart defects, syndactyly or polydactyly).

Investigations:

• Detailed ultrasound examination.
• Fetal MRI could help identify the location and type of obstruction.

Follow up:

• If the pregnancy continues, serial scans should be carried out to define the best time for delivery based on evolution of hydrops.

Delivery:

• Place: hospital with neonatal intensive care and pediatric surgery.
• Time: 38 weeks.
• Method: cesarean section with EXIT procedure and tracheostomy.

Prognosis:

• Highly lethal condition with almost all cases dying in the neonatal period.
• There are a few case reports of spontaneous resolution in utero, either because of dilatation of a stenotic segment between the larynx and the trachea or even development of a tracheoesophageal fistula with drainage of the bronchial fluid into the esophagus.

Recurrence:

• Isolated: no increased risk.
• Fraser syndrome: 25%.