[Changes in the kidney and upper urinary tract in the normal course of pregnancy. Results of a sonographic study]

In 232 women with a normal course of pregnancy the kidneys and the upper urinary tract were studied by means of ultrasonography. In 73% of the patients a dilation of the renal collecting system was found. Frequency and grade of the dilation have been increased from the first to the third trimenon, with a significant preference of the right side. A marked dilation with a sagittal diameter of the pyelon of more than 15 mm was found in only 12% of the pregnant women. In a single case during uncomplicated pregnancy also monstrous dilation could be demonstrated.