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Child Health Guideline Identifier

Antenatal Hydronephrosis

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Referral Process

Information to include in referral for postnatal scan and outpatient review:

  1. Child's name, address, date of birth and NHI
  2. Name of referring doctor, phone number, General Practitioner contact details
  3. Details of antenatal findings + copy of report must be included.
  4. Mothers NHI number
  5. Referrals that do not include this information will be returned to referrer.

Where should Imaging be performed?

The facility that performs paediatric scans should have the following:

  • Radiologist on site with paediatric interest
  • Paediatric-size transducers, equipment and settings
  • Sonographers trained in paediatric scanning
  • Digital imaging facility with images onto CD/DVD, or images in DICOM format sent to ADHB PACS.

Significant Abnormalities

A significant abnormality is suggested by any of the following:

  • Renal parenchymal thinning
  • Renal pelvic diameter >10mm
  • Bilateral renal pelvic dilatation
  • Calyceal dilatation with normal renal pelvic measurement
  • Ureteric dilatation, especially entire length of ureter
  • Ureterocoele
  • Bladder wall thickening


This should not be routinely prescribed, particularly in children who have never had a documented urine infection.

For infants being referred for a MCUG, antibiotic prophylaxis should be prescribed by the referrer to commence the day before the procedure is scheduled

US ultrasound
MCUG micturating cystogurethrogram,
VUR vesicoureteric reflux
PUJ pelvi-ureteric junction
BP blood pressure,
PUT Paediatric Urinary Tract outpatient clinic

Abdominal US should include liver, spleen, pancreas, kidneys


Where to Refer after Imaging

All urgent referrals regarding urinary tract obstruction go to the paediatric surgeon on call (contact via switchboard)

  • Infants from the Auckland DHB should be referred to PUT or Renal Clinic via Central Referrals Office, Ground Floor, Building 10, Greenlane Clinical Centre.
  • Infants from WDHB should be referred to the General Paediatric Clinics at the Rangitira Unit, Waitemata District Heath Board, Private Bag 93115, Henderson or North Shore Hospital within 6 weeks
  • Infants and children from Counties Manukau DHB should be referred to General Paediatrics, Kidzfirst, Middlemore Hospital within 6 weeks

Note: Outpatient clinic refers to either PUT or Renal Clinic at Starship Hospital, or General Paediatric Clinic at Waitemata DHB or Counties Manukau DHB
If unsure about severity of findings or where to refer, please call the paediatrician.


Antenatally detected urinary tract abnormalities: more detection but less action. Pediatric Nephrol (2008) 23: 897-904.

Outcome of isolated antenatal hydonephrosos - a systematic review and meta analysis. Pediatric Nephrol (2006) 21: 218-224.

Unilateral multicystic dysplastic kidney; long term outcomes. Arch Dis Child (2006) 91; 820-823

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Document Control

  • Date last published: 20 July 2015
  • Document type: Clinical Guideline
  • Services responsible: Paediatric Nephrology, Paediatric Radiology, Paediatric Urology, Neonatology
  • Author(s): Neil Price, Sally Vogel, Malcolm Battin, S Wong
  • Editor: Greg Williams
  • Review frequency: 2 years

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