Abstract

Antenatally diagnosed urinary tract anomalies form approximately 20% of fetal malformations. Renal pelvic dilatation forms 2-3% cases.

Embryologically, the renal organogenesis is complex involving multitude of pathologic factors. Obstruction to urinary flow at specific stages of nephrogenesis can affect renal function in different ways. The management of such cases require multidisciplinary management involving fetal medicine specialists, paediatrician, urologist and radiographers.

This study involved identification of fetuses renal pelvic dilatation amongst all renal anomalies at anomaly scan between July 2009 and March 2010. Further follow-up scans at 28 and 34 weeks were performed antenatally.

There were 44cases of renal anomalies from 3362 fetuses born during that period. There were 31 fetuses with renal pelvic dilatation, of which 25 (80%) were unilateral and 6 (20%) were bilateral. These were further categorised into mild (8-<10mm), moderate (10-15mm) and severe (>15mm). All fetuses were found to be low risk for Downs' syndrome. 87% of cases were male fetuses.

These neonates were followed up for up to 6 months age with renal ultrasound and further tests, where appropriate in the form of MCUG, MAG III or DMSA scan to achieve diagnosis, outcome and plan further management.

The study highlighted that renal pelvic dilatation >10mm are associated with poor or guarded prognosis affecting functioning of the kidney/s. Antenatal counselling by paediatrician and paediatric-urology team provided a good opportunity to understand the condition, possible outcome and care in neonatal and childhood period. Obstetric intervention in the form of early delivery is not likely to alter the prognosis.