Pulmonary hypoplasia is a congenital condition characterized by lungs that are small and underdeveloped. Pulmonary hypoplasia most often occurs secondary to a wide range of other congenital anomalies such as congenital diaphragmatic hernia, congenital heart defects, omphalocele, skeletal dysplasia, and chromosomal abnormalities like triploidy. Hydrops fetalis can be both a cause and complication of pulmonary hypoplasia. Pulmonary hypoplasia is also associated with amniotic fluid abnormalities like oligohydramnios. Isolated pulmonary hypoplasia is exceedingly rare.
Pulmonary hypoplasia has an incidence rate ranging from 9-14 per 10,000 live births. Pulmonary hypoplasia can be diagnoses prenatally via ultrasound and MRI. Pulmonary hypoplasia is common in stillbirths, and it is a common direct cause of neonatal death as it affects breathing, heart function, and overall development. The prognosis is dependent on the severity of the hypoplasia, the underlying cause, and associated diagnoses. The recurrence risk is dependent on the underlying cause.