Skip to Main Content

Key Features

  • Defined as incomplete development of one or both lungs

  • Characterized by a reduction in alveolar number and a reduction in airway branches

  • Present in up to 10–15% of perinatal autopsies

  • Congenital diaphragmatic hernia is the most common cause, with an incidence of 1:2200 births

  • Can be a result of

    • An intrathoracic mass, resulting in lack of space for the lungs to grow

    • Decreased size of the thorax

    • Decreased fetal breathing movements

    • Decreased blood flow to the lungs

    • Primary mesodermal defect affecting multiple organ systems

  • Other causes include

    • Extralobar sequestration

    • Diaphragmatic eventration or hypoplasia

    • Thoracic neuroblastoma

    • Fetal hydrops

    • Fetal hydrochylothorax

  • Chest cage abnormalities, diaphragmatic elevation, oligohydramnios, chromosomal abnormalities, severe musculoskeletal disorders, and cardiac lesions may also result in hypoplastic lungs

Clinical Findings

  • Clinical presentation is highly variable and related to the severity of hypoplasia as well as associated abnormalities

  • Often associated with pneumothorax in newborns

  • Presenting symptoms in some newborns with primary hypoplasia (without associated anomalies)

    • Perinatal stress

    • Severe acute respiratory distress

    • Persistent pulmonary hypertension

  • In lesser degrees of hypoplasia, presenting symptoms may be

    • Chronic cough

    • Tachypnea

    • Wheezing

    • Recurrent pneumonia


  • Chest radiography

    • Findings include variable degrees of volume loss in a small hemithorax with mediastinal shift

    • Pulmonary agenesis should be suspected if tracheal deviation is evident

  • Chest CT scan is the optimal diagnostic method if the chest radiograph is not definitive

  • Ventilation-perfusion scans, angiography, and bronchoscopy may demonstrate decreased pulmonary vascularity or premature blunting of airways associated with the maldeveloped lung tissue

  • Arterial blood gas analysis determines degree of respiratory impairment


  • Supportive

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.