Antenatal renal pelvic dilatation; the long-term outlook

Clin Radiol. 2007 Feb;62(2):134-9. doi: 10.1016/j.crad.2006.08.014.


Aim: The purpose of this study was twofold: first to provide data for more accurate counselling of parents with regard to prognosis, and second, to ensure that by following a policy of selective micturating cystourethography (MCUG), significant pathology is not missed, in particular vesicoureteric reflux (VUR). (MCUG is only undertaken if the renal pelvic diameter (RPD) is >/= 10 mm or if there is calyceal or ureteric dilatation.)

Material and methods: Data were collected prospectively over a 6-year period. Pre and postnatal imaging findings were collected for all infants in whom a RPD of >/= 5 mm was identified at any gestational age. The imaging records of all patients were reviewed in 2005 for evidence of pathology detected after re-presentation with symptoms. The age range at review varied from 2-8 years.

Results: Complete data were available in 527 infants. The risk of significant pathology was related to the degree of antenatal renal pelvic dilatation varying from 6% for a RPD of 5 mm at 20 weeks gestation to 38% at 10 mm. At 28-33 weeks gestation the risk varied from 5% at 5mm to 15% at 10 mm. Subsequent imaging record review revealed only one patient with grade II VUR in the study population not picked up by our selective MCUG policy.

Conclusion: The present study provides prognostic information that can be given to parents both antenatally and postnatally, and reassurance that a selective MCUG policy is appropriate.

MeSH terms

  • Algorithms
  • Child
  • Child, Preschool
  • Dilatation, Pathologic / diagnosis
  • Dilatation, Pathologic / diagnostic imaging
  • Female
  • Fetal Diseases / diagnosis*
  • Fetal Diseases / diagnostic imaging
  • Humans
  • Infant
  • Infant, Newborn
  • Kidney Diseases / diagnosis*
  • Kidney Diseases / diagnostic imaging
  • Kidney Pelvis / diagnostic imaging
  • Kidney Pelvis / pathology
  • Male
  • Postnatal Care / methods
  • Pregnancy
  • Prenatal Diagnosis / methods
  • Prognosis
  • Prospective Studies
  • Radiography
  • Radionuclide Imaging