Objective: This study has been undertaken to determine the frequency and pattern of urinary tract anomalies diagnosed by ultrasound, to correlate the prenatal with postnatal diagnoses and to identify prognostic factors.
Methods: The Ultrasound Unit's database was reviewed for fetal urinary tract anomalies detected between January 2002 and June 2012. Prenatal diagnoses made by ultrasound were confirmed by postnatal ultrasound, as well as with surgical reports. Statistical analysis was performed using the Mann-Whitney U-test, Chi-square and Fisher's exact tests. p values <0.05 were considered significant.
Results: A total of 838 fetal malformations were prenatally diagnosed by ultrasound with a frequency of 21% of urinary tract anomalies (177/838). Renal pelvis dilatation and hydronephrosis accounted for more than half of the cases (52%). The most frequent postnatal diagnoses were also urinary tract dilatations. The prenatal diagnoses corresponded to the postnatal ones in 88.8% of cases. There was a highly significant association between anterior-posterior renal pelvis diameter above 10 mm in the last ultrasound performed before the birth and the need for surgery (p < 0.01).
Conclusion: We emphasize the high degree of reliability of prenatal ultrasound in the establishment of diagnosis of urinary tract malformations and the prediction of postnatal outcomes.
Keywords: Congenital malformations; hydronephrosis; postnatal follow-up; pyelectasis; urologic surgery.