Ultrasound Scanning in Fetal Renal Pelvis Dilatation: not only Hydronephrosis.

Pelvic dilatation is the alteration of the urinary tractmost frequently detected by maternal-fetalultra-sound. Hydronephrosis is not a diagnosis; it is an imagefinding. The diagnosis is the cause that produces it. Since pelvic dilatation is relatively frequent in thenormal fetus, and the definition and diagnosis of hy-dronephrosis are difficult, once it is detected, adequate follow-up is required. Therefore, it is important for the urologist and obstetrician to understanddifferential diagnosis and clinical implications in order to offer an accurate counselling to the parents.