The anterior-posterior renal pelvic diameter (APRPD) is the preferred measure to characterize the severity of urinary tract (UT) dilatation. The likelihood of resolution of a urinary tract dilation is related to the APRPD at initial diagnosis.
The term “UT dilatation” should be used consistently. The use of non-specific terms (e.g. hydronephrosis, pyelectasis, pelviectasis, uronephrosis, UT fullness or prominence, and pelvic fullness) should be avoided.
Prenatal risk stratification:Low risk (UTD A1): APRPD 4 to <7 mm at <28 weeks, 7 to <10 mm at >28 weeks, ± central calyceal dilation, renal parenchyma of normal thickness and appearance, ureter not visible, normal bladder, no oligohydramnios Increased risk (UTD A2-3): APRPD >7 mm at <28 weeks, >10 mm at >28 weeks, or any one of the following: dilation of peripheral calyces, abnormal parenchymal thickness or appearance, visibly dilated ureter, abnormal bladder, oligohydramnios
Postnatal risk stratification: Low risk (UTD P1): APRPD 10 to <15 mm (examined >48 h after birth) ± central calyceal dilation (with APRPD <10mm), renal parenchyma of normal thickness and appearance, ureter not visible, normal bladder.Intermediate risk (UTD P2): APRPD >15 mm + central or peripheral calyceal dilation (with APRPD<15 mm), ± dilated ureter. Normal renal parenchymal thickness and appearance High risk (UTD P3): UT sonographhic findings as in UTD P2, with renal parenchymal thinning, increased echogenicity and/or decreased corticomedullary differentiation (even if APRPD <15 mm), or abnormal bladder (wall thickening, ureterocele, posterior urethral dilatation).
Comments by Evaluators:
Consensus document with recommendations based on literature evidence.
Recommendations were made by a panel of specialists, without external review.
There are future research directions that will help to improve the evidence for recommendations.