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Urology: Hydronephrosis in Newborns Referral Guidelines

Hydronephrosis means that the kidneys are abnormally dilated or overfilled with urine. There are several causes, many of which do not cause any harm to the kidneys, but in some cases hydronephrosis can be associated with poorly functioning kidneys. Hydronephrosis can affect one (unilateral) or both (bilateral) kidneys, and it resolves on its own in about half of all cases.

Initial Evaluation and Management

Your physician can usually detect hydronephrosis through a routine prenatal ultrasound during the second trimester. If so, your physician may refer you to our Fetal Medicine Institute for a high-resolution (level II) ultrasound and MRI scans to evaluate your baby’s condition.

The Fetal Medicine Institute at Children’s National may recommend further testing after your baby is born. This testing may include:

  • X-ray of the bladder to check for vesicoureteral reflux
  • Diagnostic imaging of the kidneys to assess function and proper urine drainage 

Newborns and infants with hydronephrosis usually show few or no symptoms at all. Older children who have moderate to severe cases may experience:

  • Pain in the side or abdomen
  • Blood in the urine

Older children may be more likely to get urinary tract infections, in which symptoms include:

  • Persistent feeling of needing to urinate
  • Pain in the lower abdomen during urination
  • Cloudy or bloody urine
  • Back or side pain
  • Fever
  • Vomiting

When to Refer

I. Mild unilateral hydronephrosis/pyelectasis (SFU Grade 1 or 2)
If initially seen on DOL 1-5…repeat sonogram in 3 months:

  • If improved, no further studies
  • If stable, repeat in 6-9 months
  • If worsened, refer to pediatric urologist

If initially seen on sonogram after DOL 1-5

  • Repeat in 6-9 months
  • If stable, no further studies
  • If worsened, refer to pediatric urologist

II. If associated with duplication of collecting system or bilateral

  • Refer to pediatric urologist…recommend starting antibiotic prophylaxis with amoxicillin 25mg/kg/dy until further evaluation complete.

III. Moderate or severe Unilateral hydronephrosis (SFU Grade 3 or 4)

  • Refer to pediatric urologist…recommend starting antibiotic prophylaxis with amoxicillin 25mg/kg/dy until further evaluation complete.

How to Refer

The physician referral line is 202-476-2670

If possible, have parent bring the following: 

  • Prenatal and postnatal imaging (films or CD) (postnatal sonogram at 2-3 weeks of age)
  • Prenatal and postnatal sonogram films or CD, lab work

Physician Relations

physicians talking

Liaisons respond to concerns, actively seek feedback from staff and work with practices in the community to ensure that referral processes are convenient and operating well.

Meet your liaisons