Objective: To evaluate the incidence, associated anomalies, and the type of congenital urinary tract anomaly and to know the cause of congenital hydronephrosis.
Methods: In 4.5 years, 5,442 fetuses had ultrasonography and 48 cases of fetal urinary tract anomaly were detected. Ultrasonogram was done after delivery with further examination as necessary.
Results: The incidence of all types of anomaly was 4.3% (236/5,442) and the incidence of urinary tract anomaly was 0.9% (48/5,442, 8.8/1,000 births) of all babies born and 20.3% (48/236) of entire anomaly. Types of urinary tract anomaly were as follows; hydronephrosis (37 cases), multicystic dysplastic kidney (5 cases), polycystic kidney disease (2 cases), renal agenesis (2 cases), ectopic kidney (1 case) and hypoplastic kidney (1 case). Associated anomalies were found in 8 cases (16.7%) among 48. Causes of hydronephrosis were ureteropelvic obstruction in 13 cases, ureterovesical obstruction in 4 cases, vesicoureteral reflux in 2 cases, proximal ureteral obstruction in 2 cases, and no specific causes in 16 cases.
Conclusions: Antenatal ultrasonography is a very useful diagnostic tool in the detection of urinary tract anomaly and a careful search for other anomalies is indicated when urinary tract anomaly is found.