- 1 in 50,000 births.
- 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.
- 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).
- Detailed ultrasound examination.
- Fetal MRI could help identify the location and type of obstruction.
- If the pregnancy continues, serial scans should be carried out to define the best time for delivery based on evolution of hydrops.
- Place: hospital with neonatal intensive care and pediatric surgery.
- Time: 38 weeks.
- Method: cesarean section with EXIT procedure and tracheostomy.
- 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.
- Isolated: no increased risk.
- Fraser syndrome: 25%.