Prenatal diagnosis of renal disease

The purpose of this study is to report the range of renal congenital anomalies identified by ultrasonography and to analyze the indications for the ultrasound study that lead to their diagnosis.

All cases of renal malformations diagnosed at our institution from June 2001 through May 2004 were evaluated retrospectively. The indications for sonographic evaluation were reviewed. Cases were divided into those referred for routine ultrasound screening and those referred with other indications. Results were expressed as percents of total.

A total of 117 cases of renal congenital anomalies were identified, in 14 cases (11.9%), other congenital anomalies were also present. Hydronephrosis was the most common diagnosis detected in 64 cases (54.7%). There were 21 lethal renal anomalies identified (17.9%). Multicystic dysplastic kidneys were present in 21 cases (17.9%). Renal agenesis was identified in 15 cases (12.8%). Other detected anomalies were: bladder outlet obstruction 15 (12.8%), echogenic kidneys 13 (11.1%), ectopic ureteral implantation 2 (1.7%), renal cysts 1 (0.8%), pelvic kidney 3 (2.6%), double collecting system 1 (0.8%), and unilateral atrophic kidney 1 (0.8%). A total of 94 cases (80.3%) had no indications for sonographic evaluation other than routine screening.

Relying on risk factors as indications for ultrasound studies will not detect the majority of congenital anomalies, especially those associated to the urogenital system, a group of conditions that may particularly benefit form prenatal detection.