[Prognosis of prenatal uropathies: should fetal urine tests be continued?]

Twenty percent of the children with end stage renal failure have severe obstructive uropathies. The assessment of fetal renal function and the degree of renal damage in utero is a critical factor in providing realistic counseling. The prediction of postnatal renal function is made by sonography, fetal urinary biochemistry and fetal serum for beta-2-microglobulin. Ultrasonography is a useful method including assessment of amniotic volume and ultrasonographic evaluation of the renal parenchyma. The analysis of fetal urine for the assessment of renal function leads to conflicting results. Some papers conclude that fetal urine electrolytes are not an accurate predictor of neonatal renal function, others conclude that they provide useful information. The number of studies dealing with the urinary beta-2-microglobulin levels in the assessment of prenatal renal function is too small for allowing definitive conclusions. The predictive value of fetal serum beta-2-microglobulin for neonatal renal function may be interesting but the results are yet preliminary. The studies of fetal urinary biochemistry should be continued within prospective research programs; the data are either too conflicting or too preliminary to use this methodology in commun practise.