[Prenatal screening in utero of urinary abnormalities. Management].

The major benefit of antenatal ultrasonography is to allow early diagnosis of urinary tract malformations before postnatal infection worsens the prognosis. In the majority of cases, there is a unilateral and moderate dilatation requiring a check-up only during the second week of life; treatment subsequently depends on the etiology of the uropathy and the consequences on the kidney. Unilateral severe dilatations and bilateral, but moderate, dilatations must be managed immediately after birth in a pediatric surgical center. In the rare cases of severe bilateral obstructive uropathy, in utero decompression by catheterisation or surgery is now considered to be uselessly invasive, considering that renal dysplasia is already present when the malformation is detected.