Fetal and neonatal kidney function. Implications for fetal urinary tract abnormalities

High-resolution sonography provides the opportunity for prenatal detection of fetal anomalies of the urinary tract. In view of various options of prenatal urinary diversion to alleviate obstruction, it has become a scientific goal to measure fetal renal function and to determine the prognosis of urinary tract malformations. The article outlines the accumulated knowledge of the development of fetal renal function and the diagnostic possibilities offered by sonography and by laboratory test with focus on the chemistry of the amniotic fluid. Taking into consideration the high risks of prenatal intervention, these findings are discussed as to their relevance for the clinical management of pregnancies complicated by fetal urinary tract abnormalities. Lastly, criteria are proposed for the decision making in clinical practice.