Is lung hypoplasia an underestimated entity?

Background: Lung hypoplasia is a complex disease which is probably an under estimated problem in newborns. The diagnosis may be missed since the clinic al features are highly varying. Histologic counting of alveoli is necessary to ensure the diagnosis. Pathogenesis: Risk factors for lung hypoplasia are oligohydramnios, absent fetal breathing movements, and thoracal tumors. Under these conditions phys ical stimuli are absent on which lung growth mainly depends. In the case of preterm rupture of membranes the gestational age and the degree of oligohy dramnios are decisive for the risk of hypoplasia. Postnatal growth can comp ensate in less severe cases. However, in severe cases persistent pulmonary hypertension is associated with a poor outcome. T herapy and diagnosis: New therapeutic options for persistent pulmonary hype rtension are currently under evaluation. Prenatal measurement of lung volum e and flow profile in pulmonary vessels are new issues to improve prenatal diagnosis. Conclusions: Lung hypoplasia is usually not adequately taken into account. High clinical suspicion is necessary in order to understand this disease an d to develop therapeutic strategies.