Ultrasound screening of newborn urinary tract.

A non-invasive method to screen newborn babies for ureteric reflux might allow the possibility of appropriate action to prevent reflux nephropathy. We have tested the sensitivity of ultrasound screening of the urinary tract. 1061 unselected newborn infants born during 1986 were examined by ultrasound and the findings were recorded on videotape. Babies with dilated renal collecting systems underwent further investigations (micturating cystourethrography, intravenous urography, or radioisotope study). With these methods, 11 children were found to have renal disorders. A postal follow-up survey was carried out when the children were 3 years old. 657 (62%) families responded. We searched for non-responders among children born in 1986 who had subsequently had a renal radioisotope investigation: 5 non-responders were found among these children. Of the total, 24 children had had a urinary-tract infection: 3 more children with ureteric reflux were found; their neonatal ultrasound scans had suggested no abnormality. Thus, more than half the children of this cohort in whom hydronephrosis or ureteric reflux developed had only slight dilatation (less than 5 mm) on the neonatal scan. On review of the original videotapes there was no difference in internal dimension between left and right kidneys: the internal dimension was 5 mm or less in both kidneys in 96.3% of babies and 4 mm or less in 93.3%. Routine renal ultrasound scanning of newborn babies is of no value in detecting those who may have ureteric reflux: the number of other renal abnormalities likely to be detected is small.