The lungs in congenital bilateral renal agenesis and dysplasia.

A detailed quantitative analysis was made of the lungs from 8 infants dying with bilateral renal agenesis or dysplasia. Total lung volume was reduced in all cases, particularly in those with renal agenesis. In both groups there was a reduction in number of airway generations, indicating interference with development at between 12 and 16 weeks' gestation. The alveoli in each acinus were reduced in size and, in some cases, number--although their stage of differentiation was normal for age--pointing to a disturbance of growth during later fetal life also. As liquor is largely non-renal in origin at least up to 16 weeks' gestation, it seems that there are factors other than the oligohydramnios interfering in early lung growth in these cases, such as reduced proline production by the kidney.