[The upper urinary tract in pregnant women. Physiopathologic, ultrasonic and urographic study].

This study of the upper urinary tract with the voluntary co-operation of expectant mothers, and based on 316 ultrasound examinations and 138 urographies, confirms the high incidence of uretero-pyelocalyceal dilatations is pregnancy. Compression by the gravidic uterus and the hormonal environment of pregnancy are the best-known etiologies. The frequency of associated urinary infections and the slow regression of the dilatation in the post-partum period (three months) will be noted.