Associations, follow up data, and postnatal outcome of antenatally diagnosed Urinary Tract Dilatation - Five-year single tertiary center experience from South India

Abstract

Urinary tract dilatations (UTD) are frequently diagnosed during Mid-Trimester Anomaly Scan (MTAS), at which time, given their variable progression and heterogeneous classification systems, offering suitable counsel to the couple is challenging. Based on postnatal data, we aimed to guide parental counseling, and further evaluation of UTD diagnosed at MTAS. Specifically, the utility of multi-disciplinary UTD classification system was tested. A retrospective observational study of all UTDs included from five years (2015-2020) MTAS register. The multi-disciplinary UTD classification system was used for antenatal/postnatal UTD categorization. Follow-up data were obtained from case records until the current age of children (2-6 years). Out of 527 fetal abnormalities, 103 had UTD at MTAS. Based on the third-trimester ultrasound, 49 were low-risk UTD A1, and 44 were increased-risk UTD A2-3 (including the nineteen UTD A1 at MTAS worsened to A2-3 by third-trimester). On postnatal follow-up of UTD A1 and A2-3, respectively, neonatal UTD P2/P3 was seen in 2% and 40.9%; complete spontaneous resolution was seen in 79.5% and 43.18%; none and 22.7% underwent surgical intervention; persistent P2/P3 UTD were seen on follow-up in 2% and 4.5% (excluding those who needed surgery); impaired renal function was seen in none and 36.3%, and recurrent UTI in 8.1% and 34.09%. The subgroup with progressive UTD (from A1 to A2-3 by third-trimester ultrasound) formed 43% of the final UTD A2-3 category. Among these 19 cases, surgical intervention was performed in eight (42%); impaired renal function was seen in 7 cases (36.8%), and recurrent UTI was seen in eight (42%). Given the diverse classification systems for UTD, ours is the second Indian data proving the prognostic utility of multi-disciplinary UTD classification system, specifically at third trimester scan, based on postnatal outcome. In contrast to published guidelines, our data suggests follow-up for renal pelvis anteroposterior diameter (APD) of 4-7mm at MTAS, as some may worsen. Similar progression has been noted in other Indian studies, but the classification systems are different. Contrary to the published literature, we could not suggest a renal APD cut-off as a single criterion to predict surgical intervention. Significant limitations are retrospective observational design and multiple sonographers. Our data helps guide parental counseling and further evaluation for UTD diagnosed at MTAS. The multi-disciplinary Consensus UTD Classification system, was helpful in prognostication.