An association of pulmonary hypoplasia with unilateral agenesis of the diaphragm.

During a period of 5 years, 33 newborns with congenital diaphragmatic hernia were treated. Three groups presenting with respiratory distress in the delivery room were identified. These included 8 newborns with agenesis (group 1) and 4 newborns with nonagenesis (group 2), all of whom died. There were 19 nonagenesis survivors (group 3), giving an overall survival rate of 61%. Two newborns who presented beyond 6 hours of life were excluded. No one specific arterial blood gas value or ventilation parameter obtained preoperatively could predict survival. Postmortem right and left lung weights, lung/body weight ratio, and radial alveolar counts demonstrate that agenesis is a unique subgroup with profound pulmonary hypoplasia and a dismal prognosis.