Aim: The aim of the study was to assess indications to voiding cystourethrography (VCUG) in children with suspicion of urinary tract (UT) abnormalities in prenatal ultrasonography (US).
Material and methods: We studied 93 children aged 1 day to 7 months (mean 1.4 +/- 1.3 months). Prenatal USG was done between 18-41 week of gestational age (mean 32.6 +/- 5.6). Congenital anomalies of UT were suspected in 88% fetuses with dilatation of UT and in 12% fetuses with other changes in UT. Postnatal US was done in all children between 1-122 day of life (mean 18.2 +/- 21.5); VCUG between 1 day to 13 months (mean 2.1 +/- 2.3 months), in this in 75 (81%) infants in the first months of life.
Results: Abnormal result of postnatal US had 84 (90%) children (dilatation of pyelocalyceal system and/or ureter, duplex kidney, multicystic dysplastic kidney, ureterocele). We found normal VCUG in 67 (72%) children, abnormal in 26 (28%). Vesicoureteral reflux (VUR) to 28 kidneys was detected in 20 (21.5%) children (1st--1 kidney, 2nd--14, 3rd--3, 4th--6 and 5th--4 kidneys); another anomalies in 6 (in 2 posterior urethral valves). VUR was observed in 17.3% VCUG performed before 3 months of age and in 38.9% performed later (p<0.05). VUR was recognized: in 17.2% kidneys with normal prenatal US and in 16.4% kidneys with dilatation of UT (NS); in 6 (8%) kidneys with normal postnatal US and 22 (29.8%) with abnormal (p=0.05). There was not statistically significant difference in frequency of VUR in kidney with normal (0-5 mm) and abnormal postnatal renal pelvic diameter (RPD) (11.3% vs 19%, NS). The sensivity and specifity of normal postnatal USG in detection VUR were 79% and 56% respectively, and of normal postnatal RPD were 61% and 46% respectively.
Conclusions: 1. Indication to performing VCUG in children with prenatally detected hydronephrosis should be persistent dilatation of pyelocalyceal system and/or ureter in postnatal US or another abnormalities in UT. 2. Normal prenatal and postnatal USG does not exclude presence of VUR. 3. VCUG in children with prenatally detected hydronephrosis should be performed about 3 months of life, in specially situation earlier.