PERINATAL DIAGNOSIS OF ANOMALIES OF THE U RINARY COLLECTING SYSTEM

The introduction of prenatal ultrasonography has had a significant imp act on pediatric urology. Prenatal ultrasonography is extremely reliab le for the detection of collecting system dilatation. Determination of the presence and level of an obstructive lesion is more difficult. Pr enatal evaluation of renal function is still controversial. These poin ts are discussed on the basis of 987 cases of suspected collecting sys tem anomalies seen on prenatal ultrasound scans over st 13-year period . Among these patients, 237 had transient pelvic dilatation and 737 ha d a nephrouropathy; 13% had a lethal urinary anomaly, 42% had dilatati on suggestive of obstruction, 11% had polycystic renal disease, 9% had a duplex collecting system, and 9% had reflux. Surgery was performed in 42.7% of cases; monitoring was discontinued in 13% of cases because the abnormality was considered insignificant; 24.7% of the patients w ere still receiving follow-up at the time of this writing. The highest rates of agreement between the prenatal and postnatal diagnoses were seen in patients with hydronephrosis (95%), polycystic renal dysplasia (90%), megaureter (86%), and reflux. (70%).