Prediction of CKD during Early Childhood in Fetuses with Severe Urinary Tract Dilatation

Background: Fetal urinary tract dilation (UTD), the most common renal anomaly diagnosed in prenatal ultrasound is the denominator of wide spectrum of uropathies. Currently, sufficient data are lacking to inform patient risk stratification and prenatal counselling regarding the possibility of chronic kidney disease (CKD) during early childhood.

The aim of the study was to create a multivariable model based on prenatal sonographic features for prediction of CKD during early childhood in fetuses diagnosed with UTD grade 2-3.

Methods: Cases presenting prenatally with UTD 2-3 were collected retrospectively over a period of 4 years. Primary outcome was development of CKD during the study period. Analysis of Maximum Likelihood Estimates was performed to create a multivariable model for CKD prediction.

Results: 72 Fetuses were diagnosed prenatally with two normal positioned kidneys and UTD grade 2-3. CKD was diagnosed in 12 (16.7%) cases during the study period.

Bilateral hydronephrosis, parenchymal abnormality, hydroureter and bladder abnormality were all significantly related to CKD during early childhood, the extent of UTD did not differ significantly between groups.

A combination of prenatal ultrasound variables yielded a model with discriminatory ability of c=0.949, between normal renal outcome and development of CKD during early childhood.

Conclusions: Development of CKD during early childhood in cases of severe fetal UTD can be mainly predicted by presence of bilateral hydronephrosis, parenchymal abnormality, hydroureter and bladder abnormality. These data may enlighten the path between embryological defect during nephrogenesis and renal outcome and may aid in patient risk stratification and prenatal counselling.