The 4 year outcome following the demonstration of bilateral renal pelvic dilatation on pre-natal renal ultrasound.

There is little in the literature regarding long-term prognosis in cases of fetal pyelectasis and calyceal dilatation. The aim of this study was to correlate antenatal ultrasound findings with outcome in a large group of children, most of whom had routine antenatal mid-trimester scans. 75 babies with bilateral pyelectasis and calyceal dilatation in the pre-natal period and complete radiological and clinical data were identified over a 3 year period. Pre-natal ultrasound was correlated with results of post-natal investigation and the frequency of post-natal surgery was established. Follow-up was documented to discharge or to at least 4 years of age. Prognosis was related to the degree of pelvic dilatation, but neonatal morbidity was much more likely to be associated with pre-natal calyceal dilatation and/or hydroureter. 68% (51 of 75) of babies had insignificant abnormalities on post-natal investigation, defined as either transient fetal pyelectasis and calyceal dilatation, extrarenal pelves, or transient neonatal pyelectasis and calyceal dilatation. Five babies died in the neonatal period, all classified as either moderate or severe disease. Of the surviving 70 cases (93.3%), 27% had renal anomalies that required treatment by prophylactic antibiotics or surgery. The remaining babies were conservatively managed and followed as outpatients. One child required transplantation and a further two had a severe degree of chronic renal failure by the age of 4 years. These data will be of value in prospective counselling.