Pathophysiology of congenital diaphragmatic hernia IX: Correlation of surfactant maturation with fetal cortisol and triiodothyronine concentration

In addition to pulmonary hypoplasia and an altered pulmonary vascular bed, the abnormal lung development caused by congenital diaphragmatic hernia (CDH) is associated with an impairment in the pulmonary surfactant system. The aim of this study was to correlate fetal serum cortisol and triiodothyronine (T₃) levels, known indicators of surfactant development, with maturation of the surfactant system in the lamb CDH model. Analysis of the products of bronchoalveolar lavage in CDH showed decreased phospholipid (P < .01) and increased protein concentration (P < .02) per gram of lung tissue when compared with controls, but cortisol and T₃ concentrations did not differ significantly between the two groups. These results suggest that the surfactant deficiency in CDH is not related to an alteration in cortisol or T₃ levels but may be directly related to the mechanical effects of the intrathoracic bowel.