title: Prospective study of outcome in antenatally diagnosed renal pelvis dilatation.
abstract: OBJECTIVE
  To ascertain the outcome associated with antenatal renal pelvis dilatation; to recommend guidelines for postnatal investigation and determine an upper limit of normal for the anterioposterior dimensions of the fetal renal pelvis.
  
  
  METHODS
  Infants whose antenatal ultrasound scan showed a fetal renal pelvis of 5 mm or greater were investigated using postnatal renal tract ultrasound and a micturating cystogram. Isotope studies were also performed, where appropriate.
  
  
  RESULTS
  Vesicoureteric reflux (VUR), the most common diagnosis, was evident in 23/104 (22%). In 14 infants with VUR the postnatal ultrasound scan was normal. There was no evidence of renal scarring or dysplasia in any of the refluxing kidneys. Other diagnoses were pelviureteric junction obstruction, renal dysplasia, and idiopathic dilatation. Antenatal counselling and parental information facilitated postnatal assessment.
  
  
  CONCLUSIONS
  Infants with antenatal renal pelvis measurements of 5 mm or greater should be investigated postnatally, as a significant percentage will have VUR. A normal postnatal ultrasound scan does not preclude the presence of VUR.
mesh_terms: D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007682:Kidney Pelvis / Q000002:abnormalities / Q000000981:diagnostic imaging*; D011247:Pregnancy; D011379:Prognosis; D011446:Prospective Studies; D011859:Radiography; D012016:Reference Values; D016216:Ultrasonography, Prenatal; D001743:Urinary Bladder / Q000000981:diagnostic imaging; D014554:Urination; D014718:Vesico-Ureteral Reflux / Q000175:diagnosis* / Q000000981:diagnostic imaging