Newborn infant with severe pulmonary hypoplasia presents shorly after birth with respiratory distress and need of ventilatory support. The distress is often worsened by pneumothorax.
The lungs are small with decreased number of alveoli, bronchi and bronchioli. Pulmonary hypoplasia is evaluated autoptically; gestational age, weight of the lungs and body weight are taken into account. Normal values of lung to body weight ratio matches 0.012 or more in infants of 28 weeks gestation and 0.015 for those of lower gestational age.