Antenatal Detection of Urinary Tract Abnormalities by Ultrasonography

Background and Aims: Fetal urinary tract anomalies can be reliably detected antenatally by ultrasonography. The present study was done with objective to find out the incidence and pattern of fetal urinary tract abnormalities.

Methods: A prospective hospital based study included 5450 pregnant women. The ultrasonography was done after 20 weeks of gestation and the cases found to have urinary tract anomalies were followed till 4 weeks of postnatal life.

Results: The abnormalities were found in 20 fetuses (0.36%) involving 33 kidney units. The dilated renal system was found in 24 (72.7%), multicystic dysplastic kidneys in 6 (18.2%), polycystic kidney disease in 2 (6.1%) and renal agenesis in 1 (3.0%) kidney units. Five (25%) affected babies died and they had significantly lower mean birth weight, hemoglobin and higher blood urea and serum creatinine levels as compared to survivors. Renal anomalies resolved spontaneously in 6 (18.2 %) kidney units. The ureteropelvic junction / ureterovesical junction obstruction was the commonest abnormality followed by ureterovesical reflux at 4 weeks life. Antero-posterior renal pelvis diameter and renal size were significantly higher in cases in which anomalies persisted.

Conclusions: Thus, the babies with foetal urinary tract abnormalities require close follow up in post natal life regarding their persistence and renal function.