Prevalence:

• 1 in 50,000 births.

Ultrasound diagnosis:

• Complete absence or hypoplasia of one lung, usually the right one, with major mediastinal shift.

Associated abnormalities:

• The incidence of chromosomal abnormalities is not increased.
• The association of hypoplastic right lung with hypoplastic right pulmonary artery and partial pulmonary venous drainage of the right lung into the inferior vena cava is referred to as Scimitar syndrome.

Investigations:

• Detailed ultrasound examination, including echocardiography.

Follow up:

• Ultrasound scans every 4 weeks to monitor the evolution of the condition.

Delivery:

• Place: hospital with neonatal intensive care and pediatric surgery.
• Time: 38 weeks.
• Method: induction of labor aiming for vaginal delivery.

Prognosis:

• Prognosis is worse for right than left lung agenesis probably because of greater degree of heart and mediastinal displacement. In Scimitar syndrome, mortality is about 10% due to severe pulmonary hypertension.

Recurrence:

• No increased risk of recurrence.