title: Mild dilatation of the fetal kidney: a follow-up study.
abstract: OBJECTIVE
  To assess morbidity in children with mild prenatally detected pelvicalyceal dilatation and to document the natural history of this ultrasound finding in post-natal life.
  
  
  METHODS
  A retrospective (on-going) study was carried out in 29 children (39 kidneys) with mild dilatation confined to the pelvis and/or calices confirmed on initial post-natal ultrasound scan. Re-evaluation was carried out at a mean age of 4.2 years (range 1.5-7.8). Clinically, each patient's history, height, weight and blood pressure were recorded. On ultrasound examination the renal length, collecting system appearances and dimensions were recorded.
  
  
  RESULTS
  Vesico-ureteric reflux was demonstrated in 1 of 14 infants who underwent neonatal micturating cystourethrography. During cumulative follow-up totaling 122 years, there were only two documented episodes of urological morbidity, i.e. one episode of unexplained haematuria and one of urinary tract infection. By a mean age of 4.2 years the ultrasound appearances had reverted to normal in 69% of kidneys. In 31% dilatation persisted and was unchanged or diminished in severity. No case of increasing dilatation was seen. Renal growth was normal in 97% of kidneys.
  
  
  CONCLUSIONS
  Mild dilatation of the fetal urinary tract is a common prenatal ultrasound finding. When confined to the renal pelvis and/or calices it is of doubtful clinical significance and is associated with a low level of morbidity in infancy and early childhood. Invasive investigation in post-natal life is not justified.
authors.affiliation: Department of Paediatric Urology, St James's University Hospital, UK.
authors.forename: D F
authors.initials: DF
authors.lastname: Thomas
authors.forename: N P
authors.initials: NP
authors.lastname: Madden
authors.forename: H C
authors.initials: HC
authors.lastname: Irving
authors.forename: R J
authors.initials: RJ
authors.lastname: Arthur
authors.forename: S E
authors.initials: SE
authors.lastname: Smith
mesh_terms: D002648:Child; D002675:Child, Preschool; D004108:Dilatation, Pathologic; D005260:Female; D005315:Fetal Diseases / Q000473:pathology*; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007670:Kidney Calices / Q000000981:diagnostic imaging / Q000473:pathology; D007674:Kidney Diseases / Q000473:pathology*; D008297:Male; D011247:Pregnancy; D011446:Prospective Studies; D011866:Radioisotope Renography; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal; D014718:Vesico-Ureteral Reflux / Q000000981:diagnostic imaging / Q000473:pathology