Child Kidney Dis.  2024 Feb;28(1):1-7. 10.3339/ckd.24.002.

Antenatally detected urinary tract dilatation: a pediatric nephrologist's point of view

• KMID: 2553174
• DOI: http://doi.org/10.3339/ckd.24.002

Abstract

Antenatally diagnosed urinary tract dilatation (UTD), previously referred to as antenatal hydronephrosis, is the most commonly detected abnormality by prenatal ultrasonography. Several grading systems have been developed for the classification of antenatal UTD using prenatal and postnatal ultrasonography. UTD comprises a wide variety of congenital abnormalities of the kidney and urinary tract ranging from transient UTD to more significant abnormalities such as vesicoureteral reflux, ureteropelvic junction obstruction, ureterocele, ureterovesical junction obstruction, posterior urethral valves, and non-refluxing megaureter. Optimizing the evaluation of antenatally detected UTD is essential to recognize children with important disorders while avoiding excessive investigations. Conservative approach with close follow-up is increasingly accepted as an appropriate treatment option for patients with asymptomatic vesicoureteral reflux and ureteropelvic junction obstruction in recent years. However, predicting permanent kidney damage in an unselected group of children with antenatal UTD is still challenging. The management and follow-up of children with UTD should be individualized based on recommendations from a pediatric nephrologist, a pediatric urologist, or both. Future research directed at predicting long-term outcomes of children diagnosed with UTD from mild findings to severe disease is needed to refine management for those at higher risk of kidney disease progression.

Figure

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  Fig. 1. UTD classification system. UTD, urinary tract dilatation; SFU, Society for Fetal Urology; APD, anterior-posterior diameter. a)With renal pelvic APD ≥4 mm or calyceal dilatation. b)Renal pelvic APD ≥10 mm or calyceal dilatation. Parenchymal abnormality includes cortical thinning, increased echogenicity, indistinct corticomedullary differentiation, or cystic dysplasia. Bladder abnormality includes bladder wall thickening, ureterocele, or dilated posterior urethra. For a more complete understanding of UTD classification system, please refer to the images in the article of Nguyen et al. [4].

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  Fig. 2. Evaluation, management, and follow-up for antenatal and postnatal UTD. UTD, urinary tract dilatation; US, ultrasonography; CAKUT, congenital abnormalities of the kidney and urinary tract; APD, anterior-posterior diameter; FU, follow-up; VCUG, voiding cystourethrogram; DRS, diuretic renal scan; MAG3, mercaptoacetyltriglycine. Adapted from Herthelius. Pediatr Nephrol 2023;38:3221-7 [3].

Reference

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