The fate of antenatal renal pelvis dilatation: a prospective postnatal cohort study

ABSTRACT

Background: To assess the outcome of fetal hydronephrosis, based on antenatal sonography and to find the best cutoff APD of renal pelvis which lead to surgical outcome.Methods: All patients diagnosed with isolated fetal renal pelvic dilatation (RPD) were prospectively followed between January 2016 and December 2018. RPD was classified according to SFU grading into four grades and by APD classification to 3 groups. Group I (5-9.9 mm), group II (10-14.9 mm) and group III (?15 mm).Results: Among a total of 57 patients, group I had 32 renal units, none required surgery; group II had 19 renal units, 5 (7.04%) required surgery; group III had 20 units, 11 (15.49%) required surgery. The difference in outcome between the groups was statistically significant (p=0.001). The causes of fetal hydronephrosis was transitional in 33.33%, pelvi ureteric junction obstruction in 33.33%, vesico ureteral reflux in 29.82%, and 3.5 % had posterior urethral valves. Of the 38 infants with RPD, urinary tract infection was seen in 36.84%. Thirty-four patients had MCUG of whom 29.82% had VUR. In 38 patients DTPA was performed with following results: 10.53% had partial obstruction and 14.04% showed complete obstruction.Conclusions: Fetal hydronephrosis less than 5mm runs a benign course. In APD greater than 15 mm and bilateral disease thorough postnatal evaluation and regular follow-up is necessitated for timely intervention. The best cutoff point of anteroposterior renal pelvis diameter that led to surgery was 15 mm, with sensitivity 91% and specificity 73.5%.